where are the rear o2 sensors on a 1996 camaro z28 located . are they easy to replace . all i have is a jack . thanks

 

Right downstream of the cats. They're pretty easy to find. Most people don't replace them because you can have them tuned out or buy 02 sims for less than it costs to replace them.

 

Why do you feel you need to replace them?

The driver's side can be tricky to find, because the cat is right up against the bottom of the exhaust manifold. Passenger side is easy, because the cat is under the passenger side floor.

 

The trickiest part for me was breaking them free. The drivers side came loose after a couple squirts of PB Blaster. The passenger side required a heavy dousing of PB Blaster and had to be heated up before it finally broke loose.