Hello, this is literally my first post and I hope I'm doing it in the right place. I bought a used 2011 base model WRX a few months ago and I've been loving it. Last week the CEL lit up immediately after a fill up so I got my scanner to scan it. The code was P0137 which indicates an issue with the rear O2 sensor. I ordered a replacement sensor and planned to replace it. Since then the CEL went off so I procrastinated the repair. The light came on again (same code), again after a fill up. Since then the turned off again.
My question is this. If the O2 sensor is bad wouldn't the CEL stay on? or at least every time I started the engine? Also, why is there such a strong correlation between fill ups and the light coming on? I don't want to replace the sensor if that's not the issue. Has anyone had a similar experience, or know what the issue may be.
By the way I did replace the gas cap already thinking that may have been the issue. I have also inspected the wiring harness to the best of my knowledge, which is VERY limited.
Thanks guys and gals.
My question is this. If the O2 sensor is bad wouldn't the CEL stay on? or at least every time I started the engine? Also, why is there such a strong correlation between fill ups and the light coming on? I don't want to replace the sensor if that's not the issue. Has anyone had a similar experience, or know what the issue may be.
By the way I did replace the gas cap already thinking that may have been the issue. I have also inspected the wiring harness to the best of my knowledge, which is VERY limited.
Thanks guys and gals.