On my 1996 7.3 I was sitting in my truck while it was idling in park and the rims kept rising to about 700 to 750 rims then dropping to 450 to 500 rpms. Also when I'm ddriving and I brake to a stop sometimes the rpms will drop also. Could this be fuel filter or what do you think?

 

Check the codes, then on live data, check the IPR and ICP duty cycles.Sometimes the old (grey) CPS would do that (check to make sure you have the black one). Most of the time it's worn o-rings on the IPR.

 

How do you check them? Where are they located?

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And I read the blue ones are the best and the black ones are ok and Grey ones suck?

 

I have AE on a laptop and Car Gauge Pro on my Android phone.

Other- I just explained the colors to someone else:
https://www.dieselbombers.com/ford-p...ml#post1050768
(FUNNY-- That someone else was you... LOL)

Where? If you are looking at the front crankshaft pulley, the CPS is at the 10:00 -11:00 position (upper-left of the pulley).