Checking O2 Sensor

[smokin240]

Where is it and what do you look for to see if it's working correctly? Hopefully its not too hard :-/

[BadMojo]

Don't have my FSM, so can't give you diagnostic procedures but the O2 sensor is located on the exhaust manifold back near the firewall. When I had O2 sensor problems, the car kind of hesitated and lost power around 2500-3000 RPM. Once I got over 3000 RPM, everything felt fine.

Replacing my O2 sensor with a Bosch unit fixed the above problem and gave me better gas mileage.