c02 sensor

one more question. could anyone tell me where the co2 sensor is on a 93 saturn sl2? and is it hard to replace?

The oxygen sensor is right on the front of the manifold on the 1.9 DOHC. I replaced it about 6 months ago at 120,000 mi. The service engine like kept coming on and my mileage had started dropping off over the last 20,000 miles or so. I put a new one in (really easy 10 minutes max) and pulled the battery terminal off and put it back on and has been fine every since. My mileage went back up to about 33 mpg. Runs like new.

easy mistake for a new car girl,

its 02, not c02
Naturally Abundant Oxygen, not Carbon Dioxide