2014 Sierra P0172 and P0175

Bjd1980 · March 3, 2020

Anybody find a solution for this issue?I am having the same problem. 2014 5.3 with 49,000 miles.

jwm2201 · March 9, 2020

yes mine just started doing it.

bigdaddyln · June 13, 2020

I had identical issues, took a while but traced it down to the high pressure fuel pump..fuel was leaking by it. Replaced it along with spark plugs. I have not had a single issue with it since. I figure someone is still seeing this issue.

Nate the Snake · June 24, 2020

*UPDATE: High pressure fuel pump needed replaced*

I just began having the same issues posted above in my 2014 LTZ and have only run 91 octane since getting the truck (almost 80000 miles). Has the answer for most truck owners been the injectors getting varnished?

Edited July 13, 2020 by Nate the Snake

SinisterZ71 · August 26, 2020

Had a 2014 Sierra with an L83 in the shop the other day with this exact same problem (P0172 & P0175 fuel trim rich bank 1 & 2). Identifix says the cause is a leaking high pressure fuel pump. The high pressure fuel pump can leak fuel which is then sucked up by the PCV system and ingested by the engine (causing it to run rich, especially at idle). The test they give is to unplug and cap off the crankcase breather tubes that connect to the air box, and then unplug and cap off the PCV tube at the intake. If doing this causes the fuel trims to return to normal (near 0%), then the issue is most likely a leaking high pressure fuel pump.

This particular 2014 Sierra had 160,000 miles on it so it is quite possible the seals in the high pressure fuel pump have gone bad.

Alarmguy · June 24, 2021

Has anyone checked the alcohol content in the fuel mine reads 69% very high should be below 17% I have read that the ecm needs to be re calibrated and the truck May need a firmware update I have an appointment for this in July will post an update

JFenim · October 29, 2021

I have had the same issue on my 2015 GMC Sierra, Dealer diagnosed it as the high pressure fuel pump. Anyone have any luck on getting the attached Recall Bulletin applied to their vehicle to cover the repair? The dealer didn't even mention it, I had to find it myself on google and called GMC about it, I'm waiting to hear back if it is covered or not by this, can't see why it wouldn't be.

SB-10057680-1621.pdf

WakeMeUpBeforeYou JOJO · January 26

I have a 2014 gmc sierra 1500 5.3L with 230 000 km. I just had my origianal tranny rebuilt for the first time. I had the tourque converter replaced with a billet as well. My truck has been throwing the p0172 and p0175 codes when I let it idle for more than 5- 10min. When I clear the code it doesn't come back until I let it idle again. I thought it was because of putting 93 octane fuel in my truck but after reading this forum I am realizing that it is due to the fuel injectors. I'm going to get a quote for replacing all 8.

WakeMeUpBeforeYou JOJO · January 26

On 6/24/2020 at 9:52 AM, Nate the Snake said:

*UPDATE: High pressure fuel pump needed replaced*

I just began having the same issues posted above in my 2014 LTZ and have only run 91 octane since getting the truck (almost 80000 miles). Has the answer for most truck owners been the injectors getting varnished?

I'm having the same issues with my 2014 sierra 5.3l. Do you have any updates on this issue

WakeMeUpBeforeYou JOJO · January 26

On 8/30/2018 at 5:37 PM, Firewurx said:

Just picked up my truck. Sticking injectors is what they diagnosed. The sad thing is I had to tell the first dealership to even look at the injectors and their diagnosis of a vacuum leak wasn’t even close. Second dealership said no it’s not a vacuum leak. They did a direct cleaning of the injectors and said my fuel trims came back within spec but that I had no codes stored. They then realized by the time I got there the guy that cleaned the injectors cleared the codes after cuz it sets off misfires and what not apparently. I’m too scared to plug my scanner in to check and they said just drive it for now and monitor it.

It definitely has the throttle response back so I feel confident they took care of the issue. Cost was $284. This particular place/mechanic said they’ve seen the injectors go bad and varnish up a lot on early 14’s. I got to talk to him for 15 min so I feel good about the whole deal. He gave me credit on my 4 page diagnosis/trouble shooting memo I typed up for him tho. That made me feel good.

If I was you I’d go in asking for an injector cleaning and see where that leads you. Don’t clear the codes before you get there tho so they can see if there’s anything else funny going on.

Good luck sir!

I'm having the same issue with my truck. Did cleaning the injectors fix the issue for good?

WakeMeUpBeforeYou JOJO · January 26

On 3/9/2020 at 1:58 PM, jwm2201 said:

yes mine just started doing it.

Did you get yours fixed?

Nate the Snake · February 9

On 1/26/2024 at 7:38 AM, WakeMeUpBeforeYou JOJO said:

I'm having the same issues with my 2014 sierra 5.3l. Do you have any updates on this issue

I had my high pressure fuel pump replaced and haven't had any issues since. I've also swapped to E85 for the last 3 1/2 years since its almost always a $1 cheaper in town.