1997 Nissan Quest 6-Cylinder P0135 and P0325 O2 Sensor & Knock Sensor Issues
I own a 1997 Nissan Quest with a 6-cylinder engine. I recently encountered persistent fault codes P0135 (O2 Sensor Circuit Slow Response) and P0325 (Knock Sensor Circuit). I replaced the oxygen sensor located before the catalytic converter, but the P0135 code remains. Additionally, I'm trying to locate and understand how to identify the knock sensor—specifically, Knock Sensor 1 Circuit, Bank 1. Can anyone provide guidance on diagnosing or replacing these components? Thanks for any advice. -- n2logos2@gmail.com
Don't worry about the P0325 knock sensor code—many older Nissan vehicles show this code when scanned, and it typically doesn’t cause any drivability issues. If you're still experiencing engine performance problems, consider replacing the oxygen sensor with one from an authorized dealer, re-clear the codes, and then drive under normal conditions to see if the issue resolves.