code po440 on 2002 2.2L
This is my 1st post here due to I'm running out of ideas to help my mom fix her car. My mom called my to look at her car since her check engine light had come on. She has a 2002 cavalier with a normal 2.2 L. I have a code reader and autotap software that I use to help figure out what is going on.
I checked the code and there is only one - PO440. So I do the usual and we replaced her gas cap and drove it around for a while and the code didn't reappear. She drives it and a few days later the check engine light comes back on. Same code.
I went to our local pull a part and purchased a charcoal canister, vent switch, vacuum lines, and purge valve. We replaced the charcoal canister and vent switch. She drove the car and a few days later her light came back on. This time it was PO446 (vent switch valve malfunction). So I put the old vent switch back on and replaced the wiring going to the vent switch. I checked continuity on the wiring before putting it in and it checked good. A few days later the light comes back on. Still has the code PO440. We changed the purge valve on the back on the motor. Still gets the PO440 code. This past weekend my brother and I checked the wire connection to the purge valve. Wiring looks good and has 12 volts to the purge valve with the key in the on position.
We don't get any codes for a small leak or large leak or any other code. Does anyone here have a wiring diagram for the evap system for this car? I have thought of buying a connector that would screw on to the test port of the evap vacuum line and hook up a vacuum gage and drive it around to see if the purge valve is actually opening while driving.
Anyone have any other ideas or have had past problems they solved for this code?