I have a 97 Z28 ODBII (4) 02 sensors total. I have longtubes, ypipe no cats, and have installed (1) of the (2) after-cat 02 sims. The one I installed is located at the very end of the tranny (controls driver side exhaust I thought) which is like the last plug in from the big engine wiring harness that trails from the engine down the top of the tranny, etc. I can't remember where the other 02 sensor plug is located. The pre-cats have been hooked up for 7 months since I done the longtubes, ypipe, etc and have the flat plugs anyway. I just can't remember where hte other aftercat plug was located.

 

The O2 sensor connection that is back near the tranni is actually the passenger's side rear O2 connection. The driver's side rear O2 connection is located right underneath the passenger's side header. It should be right below the 4th spark plug on the passenger's side.

If you remember the stock cat locations, the driver's side one was right next to the block, with the driver's side rear O2 being right where the factory Y pipe made the turn down the passenger's side; that's why the connection is where it is.

Thomas.

 

ahhh ok, man I sure thought it was somewhere there by the starter but am overlooking it still, I'll get under there tonight again and look around, thanks.