[laybackman]

so my jeep didnt pass smog so i took it to a mechanic and they had diagnosed the problem being the crank position sensor...also he told me it was going to be 850.00 for labor to install the sensor ...so i figured at that price i would try to do it myself...i got the part off emay for 68.00 shipped for a new part and i was told that its on the drivers side of the engine where the motor and tranny come together ...is this true ?mainly will i need to remove the tranny ?i hope not ...thanks for all your suggestions and input ...

If your CPS is NG you get no fuel no spark period. If it is running your would appear to be OK I would say.

 

[laybackman]

I think I would go and pay someone to have them scan it and read the codes. There are two different parts call cps= crank position sensor or cam position sensor. The crank position either works or don't work now the cam position could cause problems in the smog test but very little. How bad did you fail the smog test. What where the readings?

I believe that the crank sensor is suppposed to be known as KPS and the cam sensor as CPS, but it doesn't usually happen since the cam sensor is usually dependable and is not often a cause of the problems. The ECM compares what each sensor detects and make fuel/spark adjustments accordingly. If the cam sensor was off his engine would stumble badly if it ran at all and he would see the lit CEL on his dash. OBDl scanners are probably not even available at the jeep dealer anymore they would use the key on/off method.

 

[laybackman]

Most smog failures are due to a bad cat converter. If it is make sure you use a 'three way' cat converter to replace yours if it is the culprit