I'm getting ready to install an 02 simulator for the rear 02 (behind the cat) because i'm pulling a p0136 code. I searched and couldn't find anything, but i'm looking for the harness in the engine bay that runs to the rear o2, if it exists. Any guidance here?

 

It doesn't run through the engine bay, it comes out right above the rear O2.

IIRC it's accessible under the carpet under the driver's seat.

 

Found it! Thanks for the tip. There's a large hole in the carpeting under the driver's seat that it's accessible through.

 

wait a minute, for 97 maxima you don't have to jack up the car to replace the rear O2 sensor? is the hole under the seat big enough to unscrew the O2 sensor? thanks.

 

Nope. You'll still have to get under the car to replace the O2 sensor