2008 Dodge Ram 1500 5.7L Fault Codes P0403 and P0443: Causes, Diagnosis, and Fixes
I own a 2008 Dodge Ram 1500 with a 5.7L engine. The Check Engine Light (MIL) activated, and fault codes P0403 and P0440 were detected. I have already replaced both the EGR valve and the EVAP system purge valve. Despite these replacements, the MIL remains on. A dealer suggested a possible wiring issue, but this seems unlikely since P0403 (EGR System Performance) and P0443 (EVAP Canister Pressure Sensor Circuit) are separate systems and both triggered simultaneously. I have thoroughly inspected the vehicle for EVAP system leaks and found none. What steps should I take to resolve these codes or reset them? Any insights on potential underlying causes would be greatly appreciated.
If the replacement parts were OEM, the dealer's concern about a wiring issue is plausible. Properly installed components should eliminate such faults, so wiring continuity or connections may still need verification.