About little over a year ago, I bought a used 2005 Subaru outback that was rebuilt from salvage. It’s never had the check engine light off for long… soon after one faulty part is replaced, the light comes back on with a new code related to the emissions system. I’m suspicious there is an underlying problem that no one (of the five mechanics I’ve taken it to) have been able to figure out. Here is what has happened:
– January 2019: P0171 code (System Too Lean for Bank 1) – fixed by replacing front O2 sensor
– October 2019: P2096 (Post Catalyst Fuel Trim System Too Lean Bank 1) – fixed by replacing back O2 sensor
– September 2019: P0420 code comes on. I had to save up to replace the catalytic converter in March 2020.
– Now, April 2020: P0131 code (Oxygen Sensor Circuit Low Voltage Bank 1 Sensor 1).
My mechanic is now telling me to replace the front oxygen sensor again to fix this problem, just over a year since I first replaced it. He didn’t see any wiring issues or anything else wrong.
It seems like there has to be an underlying problem causing these parts to keep going bad. Any advice? I don’t want to just keep replacing these parts, especially since I just put in an expensive catalytic converter.