2003 Pontiac Sunfire EVAP System Leak: Check Engine Light Returns After Vent Valve Replacement
I own a 2003 Pontiac Sunfire and am experiencing an ongoing issue with the evaporative emission (EVAP) system. My mechanic performed a smoke test and identified a leak in the vent valve. The part was replaced, but the check engine light has come back on. Despite this repair, the problem persists. I'm now unable to determine whether the root cause was properly addressed or if there's another underlying issue with the EVAP system. Could someone provide insight into what codes might be appearing and how to verify if the same code returns after repair?
Could you please share the specific OBD2 diagnostic code and confirm whether the same code reappeared after the vent valve replacement? It's important that your mechanic verifies the fix by retrieving and monitoring the codes post-repair, as failure to do so may indicate a non-effective repair or incomplete solution.