2005 Silverado Check Engine light PO449 stays on

[SilveradoLarry]

Got error code PO449.  Replaced both the solenoid and the EVAP Canister.  Erased my OBDII.  Drove about 80 miles mostly highway but with some stop and go.  Turned engine off.  check engine light came on immediately.  Got code PO449 and PO128.  PO128 is probably the thermastat and I saw prior positng.  I am thinking (hoping) that maybe I did not drive far enough.  Does the OBD system recycle with the engine idling?  How much time?   My kit came with a third air release part that is attached to the Canister with a hose that goes to the back.  Easy to replace but I did not want to fiddle with what is not a problem.  Any thoughts?

[tbarn]

P0449 diag runs pretty much anytime the engine is running. P0449 is an electrical failure code. Check your circuits very carefully. You did replace the solenoid under the truck, right? If so, assuming it is a good part, then it can only be wiring or pcm.

[SilveradoLarry]

Thanks tbarn.  I am now thinking the error code might have been 499.  I don't have the truck with me.  All the parts are Dorman.  The Dorman Solenoid connected into the electrical clip so I did not change the wire and clip.  Then I bought a kit that had a solenoid but it had a different wire/plug configuration.  I used the the Canister from the kit (also Dorman) and the new solenoid (not from the the kit).  Is there an easy way to check the electrical connection with a two prong power tester?  Thanks.  Sorry about the code issue. 

[tbarn]

The orange wire is powered at all times. The white wire is grounded by the PCM when required. The complete circuit can be checked with a Tech2 or equivalent and a test light (not led).

There is no p0499 for this truck. However there is a p0496 which is an evap code. Most likely purge solenoid located  in the intake manifold pointing straight up. Behind throttle body.