I have a 2001 Pontiac Sunfire with OBD code 440 and bought new AC Delco cap last weekend and cleared code. Check engine light came back on after 70 miles and it's the same 440 code. Could this be a bad solenoid by the tank or something else?
Year : 2001
Make : Pontiac
Model : Sunfire
Engine : 2.2 L
hi, the car should really be checked with a smoke machine and a scanner hooked up to check for the evap leak,with a scanner hooked up you can check for the vent valve(solenoid) and the purge valve to see if they are working and to close the system(vent valve) to smoke it ,more than likely the vent valve is bad(being this is under the car and subjected to the elements,)but by smoking the evap system is the only way to really tell what is leaking and preventing the tank from building up the proper pressure,it could also be the canister that the vent valve is attached to ,so, you really need to get the system checked with a smoke machine...guy..