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Showing results for tags 'Afm'.
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We have a 2016 Yukon 6.2L which developed a rattle at approximately 60k miles. Initially I believed the source of the rattle was a heat shield, but everything seems to be tight. It has been to the dealer twice and no progress has been made to resolve the issue. The first time they dismissed the problem and called it "normal" and the second time they believe it's a broken baffle weld in the muffler. What do you think? Thanks in advance Video with several angles from under the vehicle demonstrating the issue. The problem only surfaces when the vehicle inters v4 mode. Also, the rattle is so loud it is picked up by the Knock Sensors and it pulling timing. Scan performed with HP Tuners VCM Scanner. -
Hello, 2012 Silverado 4X4 Ext Cab LC9 with 101k miles. As the title states, I have a unique situation. The cab and bed are entirely off of my truck (T-bone damage), thus I thought this would be a good time to do a DOD delete as well as any other recommended upgrades or repairs WHILE THE CAB AND BED ARE OFF! I haven't looked at too many kits yet (Scoggin Dickeys, Texas Speed, WS6Store, etc) and still figuring what I need/don't need. Definitely would like to put in a mild performance cam if it isn't too much extra. I'm new to these trucks, so I don't know all the weak spots other than the DOD system. Basically, I'm interested in bulletproofing the system much like 6.0 powerstroke owners had to do. I just heard about the oil pickup o-ring. WTH! Wow GM.... Worth it to do this at the same time as the DOD probably. Something about a AFM plate in the oil pan? But I'm open to your input. What else? something about timing chain guides??? I vaguely remember something about a fuel system issue being pretty common as well? Sorry if I am all over the place. SO many questions right now. I just got the cab off yesterday and pretty much planning on ordering what I need by the end of this week Be doing all the work myself Thanks! -
Hey Guys, I have a 2010 Chevrolet Tahoe PPV with a 5.3L LMG and a 6L80 Trans (MYC) looking to drop in a 6.2L L9H. As far as I understand it is a direct swap. Would I run in to any issues or codes as far as the L9H not having AFM/DOD? I plan on using the 5.3L PCM and having it re flashed to work with the 6.2 Or do I look for a L94 that has FlexFuel, VVT, AFM like the LMG does?
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Does anyone know if the AFM problems were solved? Should I be concerned with the AFM in my new 2016 5.3L Silverado? thanks!
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I don't know much about this system, how it operates, the stress that is placed on the lifters during cylinder deactivation. How common is this failure? Been watching some YouTube videos on the repair and it's very labor intensive...heads have to come off, etc. I see that you can buy the entire kit (lifters, gaskets) for around $500. Have a friend that told me...just change your oil, you'll be fine. The number one cause of this failure is neglected maintenance. That true? Or is it an inherited problem with the design of the system? The system came out in 2007, there must be some improvements made to it since then, no? I must say that the AFM is allowing me to get some excellent fuel economy out of a full size truck. So is this a common problem, or are there people with 200,000 on these trucks that never had an issue with it? -
Thought I’d share what’s going on with my 2012 6.2L Yukon XL. Warning its long, but perhaps it will help someone with the same issues. The short & sweet: L94 6.2 AFM motor with cold start noise. Lifters were replaced prior to our purchase about 9 months ago, and this week my dealer replaced the camshaft & lifters noted camshaft damage. Videos of noise before and after below. There is still a noise after the repair, piston slap - and would you say normal? The detailed story. Purchased 9 months ago in North Alabama. 2012 Yukon XL Denali 6.2L (L94 with AFM) AWD. 1 Owner, 89,897 miles. Apparently at 89,741 (2 months prior to purchase) the lifters were replaced under powertrain warranty, no evidence the camshaft was replaced at that time. I purchased it without that information provided. But no problem, it was running smooth at the time, warm spring Alabama temps. My dad works in parts so had a friend pull the RPO codes & transaction history for the truck, thats how I found out about the lifter work. I did a clean up oil change right after purchase then swapped to my AMSOIL batch on hand. Fast forward to November 2015 timeframe. The nights are getting cooler, and I start to notice the noise at cold starts. The noise disappears once the motor warmed up, and I mean FULLY warmed up. It would clatter for 15 miles to town. I started researching and found TSB & lots of reports of lifter noise, piston slap common with these motors. I honestly wasn’t sure which it was so I laid out my plan to try and eliminate the lifter noise possibility since it was just repaired. From the start of November I completed 3 oil/filter changes. I downgraded from my AMSOIL filters and oil to ACDELCO filters and whatever Dexos oil I could get my hands on. I removed the intake manifold and did a good cleaning of the manifold and intake valves (added a nice catch can as well). I replaced the oil pressure sending unit and the little filter (it was clean but had to check). I removed the valve covers and removed each rocker, cleaned each pushrod with a pushrod brush & B12. I then sprayed a little B12 through each pushrod onto the lifters. Then poured fresh oil over the rockers to prevent dry start. All looked good internally from the get go. After the cleaning & immediate oil change the first start up sounded good! I honestly thought some contaminates just got in the lifters and the cleaning helped. In hindsight the temp was around 60 so the sound was probably just muted. The next day a cold morning, the noise was back. Now even more of a shrill at times with any acceleration. The holidays hit and delayed my trip to the dealer. So last Tuesday I dropped it off at the dealer with 97100 miles. I simply told the service lady it had a bad cold start noise with a prior history of motor work before our purchase & to please have it left outside overnight for a cold am start. The next day she called to say the mechanic has ordered a camshaft & is trying to find out from the previous dealer if the camshaft was ever replaced. Would take a week to repair under powertrain. I had him replace the oil pump & water pump while he was doing the surgery at no extra labor cost. Picked the truck up last night. The mechanic stated he could not find any evidence that the prior dealer replaced the camshaft only the lifters at 89,741. So he replaced both the camshaft & all lifters again. Stated he did find camshaft damage & not sure if it occurred before my purchase or not since it wasn't replaced. He said the motor internally looked real good for one of this millage & the pistons were rather clean (he speculated they had carbon knocked off during its last tear down). So now, the next morning, the temp is 30 outside. I start it up and it has a similar noise to what I brought it in for. It still continues to tap for a good 15 min of driving. Piston slap? I'm hoping this is just the normal noise & we can go on for another 10 years with no major tear downs. Please set my mind at ease. Thanks! -
Hi everyone- brand new to the forum. Thought I'd throw out a question about my 2008 Chevy Suburban LTZ sitting in the shop right now waiting on a replacement GM-cert refurb engine. Should be put in in the next several days. Truck has 165K miles. Started chewing oil back in 2012 at around 80K. Was in shop 3 times in 2013 with the usual AFM issues up until the 110K mile mark when the 3rd operation was done (I think it was replacement of all pistons). All-told, about $7250 of warranty work done to truck related to AFM. Soooooo, truck recently had misfiring on cylinder 5, low oil pressure warning, drop of pressure, left on side of road. Towed to dealership. Engine not holding pressure, needs new engine. I expect the engine to have 3 yrs/100K warranty. My question is this: Should I disable the AFM with the "Range AFM Disabler" (http://www.rangetechnology.com/products/range-v8) device on this 'new' engine to (likely) eliminate any potential issues, or should I trust the newer version of this engine that was ordered will behave and perform as desired. I am also a bit confused about posts discussing 'deleting' the AFM with "kits" or having to put different parts into the engine to turn AFM off, while getting normal, expected behavior from the engine. Thank you all for any feedback. Love this forum! John -
My 2008 5.3L 4WD Avalanche with ~135K miles has recently been throwing a P0306 cylinder 6 misfire, along with a Stablitrak warning. It first happened a couple weeks ago but only lasted a day. I cleared the code and it was fine for another couple of weeks before it happened again today. It does go through a lot of oil (probably a at every 1,000 miles), and there is a clicking sound. I know from researching this the last couple weeks that its likely failure of the #6 cylinder lifter and/or plug fouling due to the AFM system design and/or old PCV cover. I intend on doing some diagnostics this weekend including inspecting and replacing (if needed) plugs/wires/coils, doing compression tests, and pulling off valve covers to look for stuck lifters/valves. My questions are: 1) Other than the obvious, is there anything else I should be specifically looking out for when running these tests? 2) Are there are any other diagnostic tests I should be doing while I am in there. 3) Assuming compression test is fine, and replacing plugs/wires stops the misfires, can I hold off on replacing a bad lifter if there is one? 4) I would plan on getting a Range tuner to disable AFM (which I should have done when I bought the truck 3 years ago) and replacing the valve coverwith the new one. If the compression test is OK suggesting there is (currently) no ring, gasket, valve, etc. damage, would these measures stave off more issues? 4) If a lifter is bad and I really need to replace it now, can I just replace the one, or do I need to replace them all? Also, how difficult is it to take the passenger side head off to access the #6 lifters? 5) If it does fail compression, am I likely screwed and looking at a rebuild or replacement? 6) Any other advice, recommendations, or thoughts? Thanks in advance!
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So I have searched Google a ton, with no luck. I am curious: has anyone tried to tune their truck in such a way to get the AFM to engage more often? There's tons of solutions for a full AFM delete. I wanna know if it's possible to go the opposite way; and increase the tolerances on whatever parameters the ECU monitors (engine loading, throttle position, etc...) To trigger V4 mode? I don't have a great need to actually do this....I'm more curious than anything....
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Looking at crew cab short bed 4x4’s with the V8’s. I just can’t wrap my head around not having low range so it’ll either be a Z71 or a Trail Boss. Been watching prices and I’m seeing Custom Trail Boss trucks starting to get close to the prices of the LT. As in within a grand or even less. Anyone bought a Custom and regret it? I have a 2011 Silverado 1500 4x4 and my wife has a 2017 Yukon 4x4. Both have the 6L80 transmission and hers has the Ecotec 5.3 V8. Very happy with that engine and transmission combo and even with less power my ‘11 moves and drives well with the 3.42 gears. Will I miss anything with a Custom instead of a regular LT Z71? 6 spd vs 8 spd? Gas mileage? Something else? -
Hey all. So, my father's 2017 Silverado (base level cluster) shows if the truck is in 8 cyl or 4 cyl AFM mode in the DIC. However, I cannot seem to find any way to tell what AFM mode I am in on my 2020 Sierra 1500 with the base level cluster/DIC. Does anyone have any clue how you can tell what mode the truck is running in? The main reason I'm asking is because I want to get one of the Range AFM disablers, and I'd like to see, live, if it ever switches in to 4 cyl mode. Thanks in advance for any help you can provide -
2007 Silverado 5.3 V8 with AFM with 180,000 miles Truck had lifter ticking sound and white smoke upon every start up which would go away after a few minutes, no check engine light Replacement list : - headgasket - valve gaskets - upgraded drivers side valve cover - valve stem seals - intake manifold gasket - exhaust manifold gasket - 8 new afm lifters - 8 new non-afm lifters - head gasket bolts - engine coolant temperature sensor - spark plugs - spark plug wires - fuel injectors - water pump - thermostat - cam sensor - crank sensor After completion of engine reassembly no longer had white smoke upon start up and no ticking sound but flashing check engine light code p0300. Code p0300 was for cylinder #1, #4, & #7 Moved coil packs between cylinder #1 and #2 to see if coil packs was bad but no change. Set engine at TDC before installing the rocker arms. All bolts have been properly torque and no parts have been left unplugged or uninstall. Any possible advice would be helpful
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Howdy all, I’m looking for some help with a new to me truck, that looks like it has a few issues to fix. It’s a 2014 Silverado Z71, with just under 150k. The problems I’m having so far are: 1. After sitting for a little while (hours -overnight) it turns over for several seconds before starting. If I just ran it, it starts normal. 3. sometimes driving it feels like it doesn’t accelerate or shift soon enough at slower speeds. 2. When going in gear it takes a while to go it seems like, or when switching from reverse to drive it seems to not start going immediately. Two days ago I checked the codes and there was one for EVAP P0446 evaporative emission system vent control circuit , and P0430 (system efficiency below threshold bank 2) This morning I go to start it and it turns over 5 or 6 times (about) and starts, and then the CEL starts blinking. I get the codes checked and here is what it has: 1. P0036 - heated oxygen sensor heater control circuit bank 1 sensor 2 2. P0037 - same as above but says circuit low 3. P0056 - same as above except bank 2 4. P0057 - same as above but says circuit and bank 2 5. P0138 - oxygen sensor circuit high voltage bank 1 sensor 2 6. P013A oxygen sensor slow response Rich to Lean (bank 1 sensor 2) 7. P013C -(Same as above but bank 2 sensor 2) 8. P0141 oxygen sensor heater circuit (Bank 1 sensor 2) 9. P014A sensor delayed response Rich to Lean, Bank 2 sensor 2 10. P0158 oxygen sensor circuit high voltage bank 2 sensor 2. 11. P0161 Oxygen heater sensor circuit bank 2 sensor 2 12. P0300 random- multiple misfire detected 13. P0430 Catalyst western efficiency below threshold bank 2 14.p0443 Evaporative emissions system purge control valve circuit 15. P0446 Evaporative emissions system vent control circuit 16. P0458 Evaporative emissions system purge control valve circuit 17.p06DA Engine oil pressure control circuit / open 18. P3401 cylinder 1 deactivation / intake valve control circuit / open 19. P3403 cylinder 1 deactivation / intake valve control circuit low 20, 21,22,23,24 and 25 are the same as the last two but for cylinders 4,6 and 7. 26. P0036 Heated oxygen sensor control circuit bank 1 sensor 2 27. P0037 Heated oxygen sensor control circuit low bank 1 sensor 2 28. P0056 heated oxygen sensor Control circuit bank 2 sensor 2 29. P0057 heated oxygen sensor Control circuit low bank 2 sensor 2 30. P0138 oxygen survivor sensor high voltage bank 1 sensor 2 31. p013A again and a couple of the other codes again.... I’m assuming/hoping these are all related to a similar problem. Fuel pump? I figured the evap and cat codes are a separate issue but not ruling that out. Any help with this would be GREATLY appreciated. Thanks.
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On Sunday March 8th I was driving my Sierra home from my parents-in law. I pulled out from a stop sign and was just getting up to speed when there was a loud bang followed by loss of power, Loud ticking noise, vibrations and a sulfur smell coming from the exhaust. I knew this was lifters instantly as it Happened to me in August of 2018, a short 11,000 miles ago. So, I took it in to my dealer who ran diagnostics and gave me the news That I would need lifters replaced yet again. Unfortunately, my power train warranty ran out December of 2019, so they told me I would owe a balance of $2900+ tax. Of course I was very upset with this news as I would have imagined the dealer would talk to GM and get this issue sorted out.. I mean it was only a few months over a year and less than 11,000 miles since they replacedall of the lifters and the cam shaft. I contacted GM myself and over the course of the last week have been working with the dealer and trying to talk to someone at GM who could help. Finally I reached a “senior analyst” who is apparently the top tier of customer assistance and she told me there was absolutely nothing they can do and I am responsible for the entire bill. I insisted that GM must know about the issues this engine has By now and should acknowledge and help their clients, but she offered no help. How can I trust this engine again? I have read many posts people have put on this forum alone with this issue of failing lifters. How can anyone be expected to pay this much for an issue that is derived likely from GMs design of the afm system? Especially after we pay $50,000+ for the truck to begin with! I do not pretend to be an Mechanical or financial expert, but I feel I have been severely wronged in this situation. I have no choice but to eat this cost and sell the truck before the lifters have a chance to fail again. I would suggest anyone doing research considering buying one of these trucks (I believe Sierra and Silverado 14-18 at least) that has the active fuel management system to rethink it. I would also go out on a limb and suggest my friends with 14-15 year Silverado and Sierras (with expired powertrain warranty’s) to consider selling them before the lifters fail on yours and you are stuck with a $3000-$5000 bill. Good luck all.- 19 replies
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Chevy passed out a 2019 Silverado information book to journalists during this week's media drive. I'm working on scanning the entire thing and sharing it here. There's a lot of information packed into this flip book. I thought the most interesting was the engine line up and an AFM vs DFM diagram. This is the best comparison blowout diagram I've seen so far. Here's the four pages related to the engines.
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Hi everyone, I just purchased a 2016 GMC Sierra SLT Crew Cab All Terrain X a few weekends ago. The AFM (Active Fuel Management) is such a pain when switching from V4 to V8 mode at low speeds (non-highway driving) because I hate the "bogging" or "hesitating" feeling the truck gives off and the exhaust tone is UGH... I had a 2007 Avalanche and used a Range Technology device to disable it. But overtime I would have to pull the device out and plug it back in because it wouldn't activate sometimes. Been reading on this forum about the Range device for the newer Sierra's and people have been having issues with them and could mess with the computer overtime. So I won't be going that route. Another option is to get a tune like BlackBear and get it disabled or set a minimum speed of when the AFM activates. But a tune isn't an option for me right now because I want to keep my warranty as long as I can. Someday BlackBear tune will in my future! So I decided to try something. For the last couple days I have been driving in Manual mode "M" and setting it to M7 (7th gear) and driving like normal (non-highway driving). I was shifting gears up ( + ) and down ( - ) because I thought that was what you were suppose to do but I found out I can just set it to M7 and not worry about shifting, it does it for me, it just doesn't go into M8 (8th gear), which I don't need when I am going less then 50mph most days. I watched it stay in V8 mode stay the WHOLE TIME! The only time it went into V4 mode was when I shifted into M8 and then I switched back to M7 and it went back into V8 mode. So I think I found a workaround without having to void my warranty with a tune or messing up my computer with a AFM disabler device. I want to get your thoughts guys, will running in Manual "M" mode ruin the transmission in anyway? Not using M8 (8th gear) for slow speeds have long term affects with that gear? I am going to do this for another week or two and report my findings. This guy is happy when my truck isn't "bogging" or "hesitating" and have full power!!!
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Hey guys, I got a 2015 Silverado 5.3l. 138,250km. started ticking sometime last winter. Would happen instantly at start up and last about 5 minutes then would fade away. Sounded like a lifter. Took it to the dealer they said they couldn't hear it. Sound went away so left it. Fast forward to this winter and as Soon as the weather started to cool down I noticed the ticking again. Took it back to the dealer said they couldn't hear it again. I went and picked up my truck right at closing, soon as I fired her up the sound was there but everyone was gone so no one to hear it. I took a video. Next day I called the dealer, sent the video. Took like a week to get back to me. In the meantime I had taken videos pretty much every time I started it. Long story short after a brief fight with them about them trying to say it's normal etc they agreed that it sounded like a noise coming from the valve train. Left my truck with them, they called me said they had to change all lifters. Went to pick up my truck and on start up the sound is still there. This was a month ago. Sent more videos and a previous video from before they did the work and they are saying they can't hear it again. Took it in in person they agreed that there's an issue again and they will look at it. Now they are saying it's possible bad injector noise but they can't figure out which one ?. In the meantime I took it to another dealership they changed the vacuum pump. After that the sound changed. Now it's no longer at start up but once the truck has reached operating temperature and is more of a dull sound. Took it back to that same dealer who did the vacuum pump and they said valve train noise and deffo not injectors. But they won't work on it because the other dealer already did. They didn't change the VLOM or the cam. I had/have no check engine lights. Truck runs awesome. Sometimes rough idle. Any ideas what it could be? -
I have a 2012 GMC Sierra with 5.3 Vortec. I had to replace one head due to damaged exhaust valve. Completed the work and truck is running but on reduced power. Code reader shows 3425-3441-3401-3449 which are the solenoid deactivation codes for the 4 AFM cylinders. I assume I have done something or missed something that is causing this to all 4 of these cylinders. Any suggestions on what steps to take to resolve? Visual inspection of wiring and vacuum hoses has found nothing. Oil was change with Mobil 1 and new filter. Possoibly in limp mode but these are only codes showing.
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Does a Range AFM disabler work on a 2017 model? Their website indicates it goes up to 2016. I can't see what should be different... but I think they are overpriced to begin with, so I don't want to shell out the dollars for it if it's a paperweight. My truck is a 2017 1500 with a 5.3L & 6 speed. I only want it so that custom exhaust won't sound stupid. Had an i2 programmer for my 16 and it won't work on my 17... so I quit with the programmer, I'll stick with plug and play if it is truly that. -
Has anyone ever got a custom tune to delete the AFM on their truck? I contacted my dealership about it and they gave me a local tuners number. I understand that it could possibly void my warranty if deleting the AFM causes a problem. But has anyone deleted their AFM and had issues? As well what cost should I expect to see to have a tuner delete the AFM.
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This may be a rather strange question, but is it possible to reset the learned driving habits? My 2014 GMC Sierra 1500 SLE 4x4 crew cab drove great for the the first year (new to about 10,000 miles). The truck was very responsive and the AFM was not bad then--it only kicked in at about 45 mph or greater and it was not objectionable. After about a year, the AFM started engaging much more aggressively and at lower speeds--the truck would periodically jerk violently when it entered V4 mode. It began trying hard to avoid downshifting, so there is absolutely no power when you turn corners or start up a hill unless you really shove down on the gas pedal. I distinctly remember a coworker saying, "What's wrong with this thing?!?" soon after the clunking and other stuff started. The dealer said it was learning my driving habits and everything was normal. Now, I have 57k miles on the truck and I really do not enjoy driving it anymore. I have about a 25 mile commute with long stretches of 35 mph speed zones. If I don't drive in M5 or activate the Range device, the truck repeatedly goes "CLUNK, lug, SQUEAK!" as the AFM engages, the truck lugs along for a bit, and goes back to V8 mode (with passive exhaust valve squeak, of course). I have noticed the clunking is much worse when the outside temperature is below about 45 degrees. The dealership says I am stuck with this behavior because it has adapted to my low-speed stretches and there is nothing I can do about it. They say most of their similar complaints come from people who drive at lower speeds. The truck has only been maintained at the dealership--I got tired of them saying I was not maintaining my last truck properly (Mobil-1 changes at 4-5k miles or 45% oil monitor remaining, coolant and transmission flushes at 30-35k, and all fluids replaced at 50k miles, mind you). I have had them do far more maintenance than recommended and I don't hesitate to throw this fact back in their face when they start to say I have done something wrong to cause the bad behavior (they said going too long between oil changes probably caused it until I told them to check their records). They tried pulling the battery and it didn't help anything. I would love to have my truck drive the way it did when it was new. I know I could get a tune, but I have an 84 month, 84K mile warranty and I don't want to risk having too many increments of the flash counter. My dealer says to get a tune when the warranty expires, but I doubt I will keep the truck that long--I honestly don't have much faith that the drive train will hold together. The constant "clunk-lug-squeak!" reminds me of the clown cars you see at a circus. Does anyone know of a way to reset the learned behavior or do I have to live with it until I get rid of the truck? I can get access to SPS if there is a way to resolve this via the dealership tools. Any help would certainly be appreciated!
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Have a 2013 5.3L Sierra SLT with afm still on and about 210k km. I’ve been reading a lot about disabling afm and all and how it drinks oil and spark plugs get coated in some nasty soot. So today I did my spark plugs to see if there was any build up. Cause they were done about 10 months ago or longer (i think). when I checked the old spark plugs 1 through 8 they all looked fairly the same and had absolutely no soot build up of any kind and my oil doesn’t seem to be burning. So my question is. Should I still disable afm? Since I bought the truck 3 years ago now I haven’t had any issues (must have been built on a wedensday lol). Should I not chance it and just do it? Or leave the can of worms un opened
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Beating a dead horse here... Have a Denali 6.2 that I just purchased from CarMax (with an extended warranty/Thank God!) Tapping sound from the start. Ran two tanks of 91 octane to eliminate possible octane knock. Took me past the 7 day return policy and 30 day standard warranty with CarMax. Didn't really bother me because of the factory warranty. Truck looked brand new. Even had the wrapping on the DVD player. Popped the hood and started looking for an exhaust leak. I found a donut/flange laying on the crossmember. Took it to the dealership. Found that the truck had two new fuel injectors and a new Catalytic Converter. Someone was searching for the cause of the sound. Dealership tightened some gaskets and said the truck was good to go. It made the deafening tapping noise on the way home. I returned the truck to the dealership. Even though I have purchased 4 vehicles from them in the past to include a current 2019 Arcadia -- they had no loaner for me. They kept the vehicle for two more days. Could not find the cause of the noise. I went back to speak with the service manager. He was not happy. He went on a ride with me and heard the noise. Claimed it was the transmission searching for the proper gear. Weird because the noise happens constantly -- to include start up and idle. Told me his 6.2 made same noises and it was normal. Finally took it back to CarMax. They sent it back to same dealer with a promise to pay for diagnostics. Miraculously, dealer finds lifters to be the issue. I'll keep updated on status of cam, etc. I think I'll trade this lemon in on a diesel or anything without AFM. Will also not be purchasing from Bob Howard GMC in Oklahoma City.- 2 replies
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So I have recently purchased a Range AFM disabler for my 2017 Silverado 1500 E-assist because of the constant stopping and starting at stop lights, exhaust drone from V4, weird shifting from V4 to V8 and my transmission liking to jerk/shifting hard every so often. After installing the Range device, it has solved my transmission issues, disabled stopping and starting at stop lights, and has been keeping it in V8 mode 24/7! The only thing I have noticed is that when I am decelerating from a speed of around 50 MPH or more, the engine will have a fast repetitive backfiring popping sound until i either get back on the gas pedal or have reached a speed of 35 MPH. It seems to happen when i am decelerating slowly and not fast, starts to backfire when it starts to downshift at around 900-1100 RPMs I have a flowmaster Super40 cat-back dual 2.5 inch exhaust with the third "cat" still on. It used to not backfire when the AFM was active BUT when decelerating, it would switch back into V4 mode. is there a way to fix this? Is there too much freeflowing exhaust? Can this backfiring through the exhaust cause any damage if left unfixed? Thanks, -Hunter
