Olde English 5
Member
- :
- 2009 Mazda5 GT
After 125,000 miles the check engine light finally came on. It had P2243 - O2 Sensor Reference Voltage Circuit Open Bank 1 Sensor 1.
So the PCM wasn't getting a voltage signal from the front (upstream) O2 sensor and was running in open loop. Before spending close to $200 on a new sensor I disconnected and reconnected it to make sure it was tight. I cleared the code and let it idle for a few minutes and everything was ok. No CEL, no codes, running in closed loop. Maybe the sensor connector had loosened a bit from vibration? I guess I'll just keep driving and see if the code comes back.
Hope this helps anyone in case you get a P2243.
So the PCM wasn't getting a voltage signal from the front (upstream) O2 sensor and was running in open loop. Before spending close to $200 on a new sensor I disconnected and reconnected it to make sure it was tight. I cleared the code and let it idle for a few minutes and everything was ok. No CEL, no codes, running in closed loop. Maybe the sensor connector had loosened a bit from vibration? I guess I'll just keep driving and see if the code comes back.
Hope this helps anyone in case you get a P2243.