Use the sensor socket to tighten the O2 sensor to three-quarters turn past finger-tight, depending on the manufacturer's recommendation. Finally, reroute the wire and attach the connector.

The fault code on oxygen sensors is one of the most time-consuming fault codes to diagnose. So take your time and don't get discouraged.

In dumbed-down parlance, the O2 sensor “sniffs” the exhaust, and depending on the air/fuel ratio levels, converts that reading into a voltage signal that’s fed to the ECU.