I post this before but no one reply. Anyway, I have OBD0 engine have 2 O2 sensors,with 1 cable each sensor. one on exhaust #1 & #4 and the other one on #2 & #3, both before the collector. The ecu also have 2 pin for o2 sensors the primary pin C16 (white cable) and the secondary pin C8 (red/blue cable). My questions is which O2 sensors goes into the primary pin (C16 pin), the #1/#4 or #2/#3? Right now, I just wiring those two O2 sensors together to pin C16. Does this will cause any problem? Thanks.

 

Wire it like it is supposed to be stock, it'll run best that way.

 

That's what I'm trying to do. Cause I don't know how the stock suppose to be.