hey everybody!!

My ca hit 94 thousand and I want to change out my o2s.All I see is 2 located at the exhuast manifold.Is there another one hidden?wheres a best plae to get replacements??


thanks

 

If there is no evidence that your O2's are bad, don't replace them. There are only two O2 sensors that matter and they are in the headers. The ones after the cat are there just to make sure the cat is working and the ECU does not use them as a basis for air fuel mixture.

 

yes it seems to be running rich

 

damn Kaiser, you pretty much defined a post cat o2 sensor . . if i didnt know better, i would say you were a smog technician . .

as for o2s trouble, i have a check engine light that tells me my o2s is bad. it seems to run a little rich so im guessing the o2s is bad . . i just have to get around to changing it. from what i remember from smog school, only the newer cars will check to see if the post o2s is efficient. so i dont think you will see a dtc for a post o2s.

 

So how do you know better? I took the course 17 years ago when emissions testing was required in Michigan. Technically it was a lifetime certification. So in a way, I am. Not like I remember a bit of it.

I used to tune Fords using SCT and we used to just shut them off on OBD II vehicles. Like you said, on OBD I it probably doesn't really matter. As a matter of fact there was no parameters in the GUI back then.

What could be done is using a multimeter on the diagnostic port to read the mv. If it cycles past 450 repeatedly and quickly while running, it's probably good. If it's a bit slow but still cycling, I like to call them lazy O2's that won't trip a code, but still isn't efficient. If it's running rich the mv will be closer to 900. Leaner is closer to 100. If it's just stationary it's dead.

 

damn lazy o2's . lol . wow , reading that makes me feel like im in the advanced clean air car course class again . gotta see that lambda on those o2s mv graph . .

 

Would a bad o2 sensor make your exhaust fume smell like gas really bad? My exhaust fumes are getting worse and worse it seems like.

 

A dying converter might.

 

u right chris i have the same problem my converter is done looking for replacement

 

could be an exhaust leak before the cat if you smell them in the car. . . or yea a cat near its death.

 

nope. no smell at all in the car. its just a smell coming out of the exhaust.