← Back to list

2002 Chevrolet Express 3500 496 - P0446 Code Not Resetting After Vent Valve Replacement

Model: 2002 3500 Chevy Express 496 Fault Code: P0446 Posted: 2016-10-17 12:29

I recently encountered a P0446 diagnostic trouble code on my 2002 Chevrolet Express 3500 496. I replaced the evaporative emission system vent valve as recommended and cleared the code using an OBD2 scanner. However, after driving over 1,000 miles, the four monitors still won't reset. I've followed all the manufacturer-recommended drive cycle procedures. Can anyone confirm if they've faced a similar issue or have any troubleshooting suggestions for this persistent P0446 code?

Related fault codes

P0446

Comments (3)

Anonymous 2016-10-17 12:53

Are there any active diagnostic codes currently stored? Any noticeable symptoms such as fuel gauge malfunction or other electrical issues? Also, does the vehicle have a remote starter, aftermarket alarm, or any added electronic components?

Anonymous 2016-10-17 16:34

No — the vehicle runs normally and there are no reported issues.

Anonymous 2016-10-17 16:51

Thinking 'out loud' — perhaps this helps: you're not actually clearing codes; you're just scanning for them, which may lead to a false assumption that no code exists. The fuel level is around 3/4 of a tank. The speedometer and temperature gauge are functioning properly. No aftermarket modifications or electrical add-ons have been installed. Additionally, the vehicle's control module power was interrupted at some point — could this be related to the P0446 persistence?