2005 Chevy Aveo P0140 Fault: Wiring Issue or O2 Sensor Failure? Intermitent Code After Mouse Damage?
Hi everyone, I'm having an issue with my wife's 2005 Chevrolet Aveo (over 100,000 miles) that's throwing a P0140 O2 sensor circuit malfunction code. The trouble started a few days ago — the check engine light came on and then went off unexpectedly. I didn't read the code at the time, so I'm assuming it was P0140. The MIL reappeared today, and after using my basic OBD2 scanner, only P0140 appeared. Given that the issue cleared itself previously, this intermittent behavior makes me suspect a wiring problem rather than a faulty oxygen sensor — especially since such codes often resolve temporarily when the fault is not fully sustained. We live in a rural area and have had recurring mouse infestations. These mice are known to climb into warm engine compartments and chew through wires. I'm concerned that rodent damage could be causing intermittent short circuits or wiring faults leading to this code. I've reset the system, and the code is likely to return. Based on my experience and technical knowledge, which is more probable: a failing O2 sensor, or damaged wiring due to rodent activity? Any insights or diagnostic tips would be greatly appreciated. Thanks, psycho
Ah yes — this is a classic intermittent P0140 case. I recently experienced the same issue with a p0031 code that came and went for several days before stabilizing after replacing the sensor. My experience suggests wiring issues are more likely in cases like this, especially when the code clears itself temporarily. I recommend checking for physical damage to the O2 sensor harness or any exposed wires near the engine bay. Rodent chewing is a common cause of intermittent faults in older vehicles with accessible engine compartments. For step-by-step diagnosis, refer to this trusted resource: http://www.obd-codes.com/p0140. Good luck with your troubleshooting!