I don't understand my Volvo 960 3.0 1995 don't have oxygen sensor.

 

Does it have a catalytic converter without a hole for the two (2) oxygen sensors, or are the holes plugged?

 

My car don't have O2 sensor on before the catalytic converter and don't have any hole for plugged

 

Ok, I'm not sure about the 95 960. I have a 97 960, and I'm pretty sure they're the same configuration. But maybe not. What does your book say? The catalytic converter on mine has two oxygen sensors--one in the front of the converter and one after. If you don't see one in the front then maybe someone has removed it and plugged it up because maybe your state/region does not require a catalytic converter for emissions requirements. If it is required, or if you just want one, I would look for that plug, remove it, and install the oxygen sensor. Or... maybe the catalytic converter you have installed is an aftermarket one that doesn't have a hole for the front sensor. I would, first, go to the book to see what your car requires. Check to see if your state/region requires one. Check to make sure the right converter is installed. And go from there.

 

the 1995 should only have one oxygen sensor....it should be located on top of the cat....if i remember my 95 parts car correctly

 

Right. So it sounds, according to tiendainguyen's response, "My car don't have O2 sensor on before the catalytic converter and don't have any hole for plugged," that the converter has been bypassed. And if it weren't for my states emission requirements, as many times as I've had the CEL glaring at me because of a P0422 code, I might have long ago bypassed mine. But not really... I appreciate the engineering that went into establishing such a system.