sounds like a miss

[itzdalton]

2002 auto with 95k. just started it at lunch today drove about a mile and a half perfect, then started missing and knocking real bad. seems to have almost normal power, not a huge loss of power. the check engine light came on and a few times it went off, and when the light went off the truck ran fine. like it never had a prob before. then a few seconds later the light comes back on and runs like a bag a crap. is it bad to drive it like this? i need to get to work and wont have time to fix it until saturday. starts up fine. i unplugged the icp to see if that was maybe it, and it almost died when i did that. so im assuming thats fine. my scanner said no codes. what scanner do i have to use to pull codes? any other possible things that could be causing the miss/bad knock. like i said, periodically the check engine light will go out and it will run fine. then the light will come back on and it will start missing again. KOEO there is no check engine light. just while running. so im kinda confused.... i replaced the CPS, and still have the issue. Next i was thinking UVCH but i dont wanna buy them if i dont need them. any input?

[dannanw]

use a snap-on or AE quality scanner, it'll give you stored codes. by the sounds of it I would say uvch or ipr/icp but a scan will help out most.

[itzdalton]

i unplugged the icp and it almost died, how would i test to see if the ipr is working?

[dannanw]

you did check it, the computer will set it at (not 100% sure on psi) 750 as a default, so you did test it as best one can without scanner to watch PID's. You can also ohm out the uvch's to see if something's going on....if you dont want to buy a set then I'd try the 50 cent mod and recheck ohm's, fixed a customers/friends truck doing this.

[itzdalton]

i checked the icp, how do i test the ipr? thats down by the hpop, but im unsure on how to test it. i dont mind buying new uvch, i just wanna be sure thats what i need before i buy them.

[dannanw]

you did test it the best one can.... and thats why I said try the 50 Cent mod and/or ohm test first

[itzdalton]

okay, why do ya think if its uvch it would periodically work and then start missing again?

[itzdalton]

here is a vid of it running...

7.3 engine miss - YouTube

at 1:55 i hold the camera on the steering wheel and you can see how bad its making it vibrate. it viberated really bad with any load on the engine.

[itzdalton]

i got a hold of a snapon scanner from a friend and it said "p0000 no fault. vehicle okay to drive."

why does the check engine light come on if there are no codes?? this is really stumping me.

[dannanw]

It would have a code stored in memory... I would check out the harness for chafing. Other than that hard to tell on the Internet.