zzjakect

Car threw a P0455 code after a check gas cap notice showed on dash. Put new AC Delco cap on. Reset code. It is fine until fuel level drops below half a tank, Then same gas cap notification and then engine code. Any ideas?

LowRyter

1. Change out the EVAP system (right rear of the car)

if that doesn't fix it

2. Get a new car battery

zzjakect

Battery is new.
How does one go about changing EVAP system?

LowRyter

I had my local shop (oil change joint) do it. I think it was $30 for the part and 1/2 hour labor ($75 total).

The EVAP consists of the gas cap and the EVAP unit that behind the left rear. Check the full read out on your codes. Even Autozone can give you the read out.

I had the CEL come back on after I changed the cap and the EVAC. I would have it switched off and it would come back on in a few weeks. I put in a new battery and it went off immediately and hasn't been on since.

LowRyter

well, I jinxed myself. The CEL light came on again. Had it shut off...again.

buckmeister2

same thing happened to me 2 months ago. I replaced the ACNogo with a Stant cap, shut off the message, and it has not come back since. Might work for you.