I posted earlier about a starting problem I've had on/off. The first time it happened was after stopping to refuel after being on the road for about 4 hours. The car wouldn't start, even after letting it sit for a bit. Finally, I pressed the gas peddle all the way down and it fired up (acted like it was flooded). Fast forward a month later, the wife was driving the car, sitting in the traffic, it nearly died. It didn't, but it did throw a check engine light with a code of P0496. P0496 is an evaporative emission system high purge flow error. After doing some research, this code comes up on a broad range of GM cars so I had the valve replaced today at a Chevy dealer for $71. The check engine light is off and it's running fine now. I'll update later. Just an FWIW.

Let me know how it goes. I swapped out mine and 2 months later its now doing the same thing again with the same code PO496 =(

exact same issues and fix as mine, been running great for a couple months now.:D

So far so good, it's been running pretty well (knock on wood)! :thumbsup:

If it is what I think it is or rather was, you have a condition that we used to refer to as "flow during non-purge".
Basically the engine is sucking fuel vapors from the canister into the engine which will severely enrich it.
If the computer doesn't know this is happening the fuel mixture won't be right and it will not run well.
You probably killed two birds with one stone on that one.

If it is what I think it is or rather was, you have a condition that we used to refer to as "flow during non-purge".
Basically the engine is sucking fuel vapors from the canister into the engine which will severely enrich it.
If the computer doesn't know this is happening the fuel mixture won't be right and it will not run well.
You probably killed two birds with one stone on that one.

Thanks for the post. That's exactly what was happening.
Ed

I posted earlier about a starting problem I've had on/off. The first time it happened was after stopping to refuel after being on the road for about 4 hours. The car wouldn't start, even after letting it sit for a bit. Finally, I pressed the gas peddle all the way down and it fired up (acted like it was flooded). Fast forward a month later, the wife was driving the car, sitting in the traffic, it nearly died. It didn't, but it did throw a check engine light with a code of P0496. P0496 is an evaporative emission system high purge flow error. After doing some research, this code comes up on a broad range of GM cars so I had the valve replaced today at a Chevy dealer for $71. The check engine light is off and it's running fine now. I'll update later. Just an FWIW.



Wouldn't this be covered under emissions warranty??

I was told by the dealership that No, it wasn't. :banghead: