Howdy. I'm getting the P1131 code on my sister-n-law's '99. As I understand, this means there is a lack of a heated O2 sensor on the upstream. Can anyone tell me exactly where that O2 sensor is? Is it fairly close to the manifold? Or is it further down?
Dang, I forgot it has an O2 sensor on either side. Is it possible to test the sensor for continuity with a meter to find out which is bad? If so, what kinda reading am I looking for?