Look under the hood, the front of the engine, on the exhaust manifold. It should be the only thing with wire/s on the manifold. You will need a special socket to remove it. The tool is available to "Borrow" from the folks at AutoZone. If you need any further info, just gimme a shout.
Actually it depends on the engine. The 2.3/2.4 has the exhaust manifold on the back side of the engine - between the engine and firewall. You'll most likely have to get under the car to remove the O2 sensor. On the 2.2 the exhaust manifold is on the "front" of the engine between the engine and the front crossmember. You should be able to get to this O2 sensor without getting under the car (note I said *should*). Either way they're located on the exhaust manifold, before the catalytic converter.
where is the oxygen sensor in a 1995 gmc jimmy
This question is very wide. But, I would suspect the speed sensor.
just ahead of the catalytic converter
What this trouble code means that the input power(+) to the speed sensor is low.
right in front of the catalitic converter
Where is oxygen sensor on 4.3 liter 1995 Chevy S10. All O2 sensors are threaded into the exhaust system at various points, and you probably have more than one sensor.
AnswerIt is located under the intake manifold on the left side of the oil filter.
To test a 1995 Cavalier crank sensor you would need to get a mechanic's computer. They can put a sensor/fuse tester on it and see if it is working properly.
The check engine light would come on.