2003 Jeep Wrangler Sport 4.0L - P0031 and P0132 OBD2 Codes: Fuel Consumption Increase, Loss of Power After Sensor Replacement
Hi everyone, I recently purchased a 2003 Jeep Wrangler Sport with the 4.0L engine, and since then I've been experiencing persistent OBD2 fault codes P0031 (HO2S Heater Control Circuit Low - Bank 1 Sensor -1) and P0132 (O2 Sensor Circuit High Voltage - Bank 1 Sensor 1). I was advised to replace both the HO2S Heater Control Circuit Low sensor and the O2 Sensor Circuit High Voltage sensor, both located at Bank 1 Sensor 1. I replaced these sensors with OEM Mopar parts purchased from a Jeep dealership in my country. Despite the replacement, the check engine light remains on, and the codes persist. In fact, the vehicle now consumes nearly double its previous fuel consumption and lacks power—driving feels like operating a heavy truck. I'm concerned that either the sensors themselves are faulty or there's an underlying wiring issue. Could it be that the sensor is not properly installed or that there’s a short in the signal wire? I’ve also noticed that the vehicle doesn’t respond as smoothly to throttle inputs. Any insights, troubleshooting steps, or recommendations for diagnosing this issue would be greatly appreciated. Thanks in advance!
You mentioned replacing both sensors, but P0031 and P0132 refer to the same sensor (Bank 1 Sensor 1). This suggests a potential issue with either the sensor or its wiring. Please confirm whether you used OEM or aftermarket parts—sensors sold at auto parts stores like AutoZone or Advance Auto Parts have been known to fail prematurely. Additionally, inspect the O2 sensor wiring and connectors for corrosion, physical damage, or abrasion that could interfere with signal transmission.