92da6

i did a search on this subject a few times, and i've found quite a bit of helpful info. Would it be better to take off my dc header and put a stock one back for emissions? The car is running super rich because the person who did the install on the motor only wired up 1 o2 sensor. It's a 91 b16a. Could this be the reason why i'm not passing smog? Also if you know another way around it for now so I can at least drive the car, it would be helpful, thanks in advance.

Slurp56

I would think having both O2 sensors operational would affect your emissions. I think personally I would do this before trying any other tuneup

mobrep

on a 1st gen b16 it shouldn't matter. check your timing and ofcourse all the normal wires, plugs, cat and all that good stuff.

johnzm

having 1 o2 wired instead of both DOES MATTTER for emissions

johnzm

Early VTEC engines use two oxygen sensors arranged to read one cylinder pair per oxygen sensor. The mixture for each cylinder pair is tuned separately. It is important not to wire the sensors around the wrong way, otherwise one cylinder pair will run lean, and the other pair rich. It is also important not to wire one oxygen sensor into both sensor inputs, otherwise the engine will run either very lean or very rich.

http://hondata.com/techclosed.html

mobrep

i knew each o2 sensor read a pair of cylinders. didn't know they were tuned separately.

Slurp56

Yes, I failed emissions the 1st time because of this. My wire harness was never intended for my car and I couldnt find anywhere that said which was primary or secondary O2 sensors. Also having them wired backwards caused 1 set of cylinder to run very lean and the other set very rich. The car stuttered and bogged.... bad juju