O2 sensor
 

1981 911sc.....if i remove the O2 sensor and adjust the mixture, will i have to put it back when i get the california smog test?
tx!john

I recently changed the O2 sensor on my 1982 911 SC. I did some research on the topic before replacing it with a new one. One thought, the research that I did indicated that the O2 sensor is very key to the "real time" proper fuel adjustment/mix for the CIS system. If you have retained the CIS is really is not advisable to pull the O2 sensor out of the loop. I experienced a significant improvement in general performance of the car be installing a new O2 sensor. If you have gone to webers or pmos then this may not be applicable. Dempsey's 101 Projects for Your Porsche 911 has a good section on the CIS. Book is absolutely worth the $30. Hope this helps, also if the O2 sensor is not in the car and you have to go through CA DMV to relicense the car, they will inspect for it and not license if they can't find it.SmileWavy

You will at the very least have to plug it back in for the smog check.

Coop, what he is talking about (I think) is that on 80-83 911SC's (CIS w/ lamda)can idle smoother and have better throttle response if you unplug the O2 sensor and set the mixture to 3.5% CO. More details here:

http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=4433

http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=8645

Tom