How do you change the O2 sensor on a 1994 Saturn SC2?

Answer 1

the o2 sensor is located right in the front of the engine on the exhaust manifold. it's that big rusty lookin thing. the o2 sensor is the bolt lookin thing coming out of it with the wire attached. unclip the wire and loosen it with an appropriate sized wrench. you may need some liquid wrench for this to penetrate the rust. once it's out ( it will take some muscle) toss it and simply screw the new one in and tighten it with a wrench. clip the wire back up and you're ready to go.

Be sure and put some anti-sieze on the threads before you install it.

As long as you are not reusing the old sensor you can cut off the wires at the sensor and use a 7/8' deep socket to remove the old one.