the 5 cylinder colonel

[midnightcarving]

ok, so this is a new post relating to my "most challenging problem" thread...

background info :
95 4x4 4 door explorer 104k

runs predominately on 5 cylinders, shutters, misfires, and occasionally will pick up the missing cylinder, problem has been developing over the past week or so, started off dropping the cylinder occasionally, stuttered for a second and picked back up.. now it runs like this all the time.

i'll post the results of both KOEO and KOER tests... and what i've replaced already.

Test Results:
KOER:
337: EGR feedback high

KOEO:
337: EGR feedback High
336: PFE high
327: EGR feedback Low
157: MAF Low/Grounded
175: O2 sensor not switching, system at adaptive limits: left or front

What i've replaced:
MAF sensor, no result
PFE sensor, also no result.

any insight appreciated: i'm starting to think i might have a bad PCM, these codes don't seem to link together to one thing.

also i've though i might have a clogged cat or something, any thoughts?

Edit: i've also tested the EGR and new MAF : both pass.

 

[Turdle]

Check the wiring to the driver side upstream 02 sensor-they often come loose and rub on the front drive shaft. The sensor itself is right below the transmission.


It is also possible an injector is not firing reliably. This would account for a dropping out cylinder. Time to read your spark plugs