So, OK, our Jeep, 99 Cherokee sport, 4.0 Auto, 4wd is throwing all of these codes. I was reading on how to test the sensors and step one was to check for spark...pulled #3 wire, checked for spark, strong bright spark arcing all over the forked electrode on the almost new plugs. As was expected after the coil, cap and rotor being replaced recently.
Crank, no start, spray starting fluid into air intake, still no start or attempt to start...But I have spark and compression, why did it not attempt to start when fuel was introduced?

Camshaft position sensor was recently replaced as was the Crank sensor, exhaust manifold, both O2 sensors, Throttle position sensor.

Any ideas? Anyone?

 

did you try checking the harness for chafing. Might wanna look there.

 

Thanks for the helpful reply.
We've been chasing codes for near 7 weeks now, We have given the wiring harness a good looking at, tested for base voltage at connectors, cleaned connectors, applied dielectric grease to connectors...
This morning after doing the battery disconnect, reset cycle, it started right up, came to temp and no codes...
Drove it around block, fine...Guess I'll daily it until it tells me something is wrong...

We have not been just throwing parts at it, every part was replaced because a code told us it was not functioning properly, or in the case of the exhaust manifold it was leaking, except the cap and rotor, which were replaced because they are cheap and it had been 2 years.

 

Let us know what happens.