CEL problems

[4x4explorer1994]

I've searched all over this site to find my answer. Over summer my check engine light was off but lately it comes on when im at high rps near 2500 and up and if i run it there it will come on (cel) and stay on and when it gets to lower rps it will stay on but sometimes click off also feels like its lacking power recently. any thoughts ? also went through mud and everything got covered could it be a vacuum line or something plugged up?

 

[MrShorty]

1st step would be to pull codes from the computer (see doonze's thread in the stickies of this forum). Post the codes here and we'll help with the diagnosis from there.

 

[4x4explorer1994]

it comes up clear nothing nada 111 111

 

[MrShorty]

It is interesting. Whenever that CEL comes on during normal operation, the computer should remember (for 80 drive cycles) the fault code for the fault that it saw.

I note that you only posted one pair of 111's. You should get 2 pairs of 111's (one for KOEO codes and one for CM [memory]codes). Is there any chance that you did not let the KOEO test finish and output the CM codes?

If the computer is failing to store codes, I would be tempted to check the power/ground circuits to the PCM to make sure there isn't some loose connection interrupting power/ground to the PCM.