rsSteve
New member
For a while I was getting a CEL of P0496 but searching on here wasn't giving any exact solutions besides "take it to the dealer". I was finally able to resolve this issue with out taking it to the dealer. Your issue might be different than mine but I will explain what my symptoms were and the part i replaced to fix it in case anyone else searching has this issue. You can read about this code here P0496 EVAP Flow During A Non-Purge Condition
The first time you get this code try to make sure your gas cap is fully seated. Mine would trigger most often in the morning on a cold start (car was sitting all night). Whenever I would get gas, after filling the tank, i would try to start my car but it would crank over for a really long time (10-15 sec) before it would finally start. This would only happen after fill up. After i would get it running the idle would be really shaky and sputter like it was going to stall.
After some research with this conditions it was most likely the Vapor Canister Purge Valve which was faulty. They can go faulty over time or if you try to "top off" your gas tank. Apparently even doing so one time can cause it to fail. This part is easily accessible sitting in the back of the engine bay on top of the Intake Manifold. It took no more than 5 min to swap it out and it only costs ~$20, so instead of hassling with the dealer I did it my self. Here is the link to the one I used Amazon.com: ACDelco 55573017 GM Original Equipment Vapor Canister Purge Valve: Automotive
I have been running the new purge valve for 2 weeks now and 3 gas tank fill ups. I haven't received any more CEL's and the idle has actually smoothed out. Starting my car after fill ups have returned to normal as well. :banana:
The first time you get this code try to make sure your gas cap is fully seated. Mine would trigger most often in the morning on a cold start (car was sitting all night). Whenever I would get gas, after filling the tank, i would try to start my car but it would crank over for a really long time (10-15 sec) before it would finally start. This would only happen after fill up. After i would get it running the idle would be really shaky and sputter like it was going to stall.
After some research with this conditions it was most likely the Vapor Canister Purge Valve which was faulty. They can go faulty over time or if you try to "top off" your gas tank. Apparently even doing so one time can cause it to fail. This part is easily accessible sitting in the back of the engine bay on top of the Intake Manifold. It took no more than 5 min to swap it out and it only costs ~$20, so instead of hassling with the dealer I did it my self. Here is the link to the one I used Amazon.com: ACDelco 55573017 GM Original Equipment Vapor Canister Purge Valve: Automotive

I have been running the new purge valve for 2 weeks now and 3 gas tank fill ups. I haven't received any more CEL's and the idle has actually smoothed out. Starting my car after fill ups have returned to normal as well. :banana:
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