2001 cavalier 2.2 I4 crankshaft PS location

[cavalieronyc]

Hi i have cylinder 1 misfiring after i changed both O2 sensors all 4 spark plugs, new spark plug wires, ignition coils, catalyic converter, fuel filter, run 93 octane all the time, new battery, $100 worth of fuel injector and cleaning chemicals and now i need to change the crankshaft sensor where is it located? also pcm is not showing any activity and no connection from engine or transmission with chck engne light on? please help me

[J-Ri]

Do you mean you still have a misfire after replacing all that stuff or it started after replacing it?

A misfire specific to one cylinder is most likely not the CKP sensor. Also don't run 93 octane unless you've got that thing built to require it. I think yours only needs 87. Higher octane carbons up the intake, valves and pistons (which can cause a misfire). There's no reason to use it, it's no better than low octane, it just burns slower for high compression or forced induction engines. Where you get gas is much more important than the octane. BP and Shell are good. There are more, but those are the only ones that have 93 octane in this area (which my car requires)

Try a compression test before you go replacing the CKP sensor, and I'd check the fuel injectors for flow and leaks too.