99 Silverado check engine code P440
 

Have replaced gas cap, purge valve, pcv and grommet. hoses look good. Any suggestions. Light is still coming back on. with same code.

RE: 99 Silverado check engine code P440
 

have u replaced the evap canister? we have a lot of problems with those at the dealership ppl drive down dirty roads alot and they get plugged with dust.

RE: 99 Silverado check engine code P440
 

I'm assuming you mean P0440... check everything around the canister... do you smell gas ?

sometimes people forget that air filters and, fuel filters, fuel pressure regulators are all integral parts of the emission system.......... when did you change the air filter last? i would start there by checking it, then clear the code with a diagnostic tool.