P0432 and P0441 Fault Codes in 2000 Jeep Cherokee Sport 4.0L V6 with AW4 Transmission (231J) - Catalyst Efficiency and EVAP System Diagnosis
I recently encountered both P0432 and P0441 fault codes simultaneously on my 2000 Jeep Cherokee Sport 4.0L V6 with an AW4 transmission (231J). Fuel efficiency has not noticeably dropped—my vehicle is still achieving approximately 17-20 MPG on the highway. I'm wondering if a malfunction in the evaporative (EVAP) system could be triggering the P0432 code, which indicates catalyst efficiency below threshold for Bank 2. This model features a 4.0L six-cylinder engine with two pre-cat oxygen sensors, but I have not yet located the post-cat oxygen sensor. Given that this vehicle has a single exhaust system, how is it possible to have two O2 sensors, let alone one dedicated to monitoring post-catalyst performance? Any insights into the expected location of the post-cat O2 sensor or whether EVAP issues can directly cause P0430/P0432 codes would be greatly appreciated. Thanks, Jeff
I'll try to share a diagram later. Did you use an OBD-II scanner? Do you own one? Also, could you confirm whether your Jeep is a federal or California emissions model? For federal-emission vehicles, the post-cat O2 sensor is typically located on top of the catalytic converter—sometimes obscured by a shield. I’ll add more details about the EVAP system soon. Busy day here—does your Jeep remain stock (no modifications)?