I have a obd2 ls with turbo and i have an o2 sensor on the manifold but i can not find out where it plugs in to? I looked at my old manifold and it did not have an o2 sensor on it anywhere and no bung for it. I have the secondary one hooked up but need to find out where to plug the primary one in at. and someone told me it is a 1wire but i am 100% sure it is a 4 wire someone help please

 

most likely the sensor on the manifold is for a wideband o2 and someone put a stock one in there, you can do that but the reading will be off since its on the runner and not in the downpipe and youll have to extend the hell out of your harness, my suggestion, get a bung and put it back down where its supposed to be on the downpipe and plug the one on the manifold with a plug.

 

so what you are saying is plug the one on the manifold and just hook up the one on the down pipe? and it will run fine with just one o2 sensor on a obd2

 

if you have one in the manifold, your gonna have to extend your harness and you might flash a cel code because of how close the sensor is to the exhaust ports, the stock o2 sensor is not designed to be that close and might flash a code from excessive heat or damage. if you have an o2 bung(place to put o2 sensor) on the downpipe near the cattalitic converter where its supposed to be, take the o2 and put it there and use the stock plug and harness and plug the one on the turbo manifold with a bolt or 02 bung plug because you wont need it unless your tuning with a wideband 02 sensor. this should be basically putting everything back to where it needs to be and thus run correctly.

 

thank you i am goin to do that today