gas cap code

check engine light came on about a day after getting gas for the first time. i just figured it was a code the previous owner erased to sell the car. and i went to autozone (i know :rolleyes: autozone) to get the code read and he said it was a gas cap. mine had a dried up cracked seal so i bought a new one and the SES light is still on do i have to get that erased or will it go away in a few ignition on cycles?

P0440? Should turn off by itself after 3 consecutive ignition cycles the diagnostic runs without seeing a failure, stays in "history" for 40 cycles after light turns off.

Clear the code with a scanner, disconnect the battery for several minutes, remove the PCM memory fuse for several minutes, or wait numerous drive cycles.

And only late model Fords have a true gas cap code. P0440 on GMs is a generic evaporative emissions system fault, and could be many things, gas cap included.

what could all be responsible for P0440?

Gas cap, fuel filler neck, gas tank, fuel pump wiring harness, fuel pump seal, numerous hoses, EVAP canister, EVAP canister vent valve, EVAP canister purge valve, PCM, wiring, etc etc.

yeah makes sense. the light still isnt off after about 4 days with the new gas cap, i just have to get a modis hooked to it and clear it and go from there i spose

yeah makes sense. the light still isnt off after about 4 days with the new gas cap, i just have to get a modis hooked to it and clear it and go from there i spose

Surely you didn't buy one of those WAAAY overpriced heaps...

nope our shop owns one i have no reason to buy one lol i could buy almost a whole nother Z for the price of one of those