Stl94LT1

The 96/97 are different, they are OBDII.

djskiggz

LOL im blind. Nevermind I found the sensor. Yup the stupid mechanic replaced the wrong one. Dumbass!

mdenz3

7/8" or 22mm. I've never had issue rounding them off, but if you live in the rust belt, be ready for a fight.

Stl94LT1

It was probably easier to reach than the one that needed changed.

twcblackhand6970

mine has two also.

sbs

Unless you have codes, leave them alone.

While I am one who preaches 30-50k front O2 changes, there is absolutely no reason to change a rear O2 until it throws a code.

andysc

having the tool is the preferred way to go, but you can rent one from Autozone. You do need a 3/8 ratchet and probably a extension or two, but o2 sensors you don't really change a whole lot, so if you want to try to do it once in a while this may be the way to go.

tia

andy schuck

Injuneer

No. 93-95 single cat cars have only two O2 sensors, one in each branch of the Y-pipe (driver's side is actually in the base of the manifold), before the cat. There is no after-cat sensor on the single cat, OBD-I cars.

Stl94LT1

I was refering to the OP's 97. Guess I should have stated that.