O2 sensor, where, and how do i check it?

[Toahk]

Many have suggester my lack of power and mild backfires can be associated with this, and was wondering how i can check if its bad, or even where it is, thanks.

[daniel240]

if you have a bad O2 sensor than your check engine light should come on and it would tell you. mine came on when i had a bad O2 sensor.

[mattlord42]

Well you could be in my boat and have a check engine light that doesn't work. As for the sensor's location it is on your header down toward where it joins your exhaust. The bolt on mine was around 20mm but I don't remember exactly. As for checking it, pull it out. If it is all black and corroded looking it is probably bad. Oh yeah, I think you can also read the ECU codes to find out if it is bad.

Matt

[Dragon240]

Yep ECU codes will tell you and when you first turn your car on (not cranked) check engine light will come on (Diag Mode 1 "bulb check")