96 jeep cherokee replaced plugs, wires, fuel filter, cap, and rotor still running rich, and getting some black smoke from it, plus losing powee at times coming up hills..

Crown automotive parts, sensors, update them all. find the supplier using that name on the internet and dont use aftermarket parts was what got the last one out of our driveway...(amongst other things, like wiring harness repair, new computer, etc oh, and update any unperformed recalls before you sell it.) You can manually clean the injectors yourself if they are dripping, theres vids on u tube. ECT ACT O2's MAP , allthe sensors, and if coolant leaks? fix that too. we found out the hard way.

Thats the XJ, the cherokee, so you must have, straight 6, 4.0L, short wide radiator with dual fans, They are a neat little rig but you have to feed them, they eat "Crown" after almost 20 years. and a timing chain is only 20 bucks at autozone, the waterpump is like 23, depends where you are with yours. miles, etc. There were some service bulletins that applied mostly wiring updates were supposed to simplify. But those sensors, that can be the thing, I proved it on one by going to the wr yard and getting a handfull of them to substitute. Some guy wrote a book about it, it turned out.

Yea its the straight 6, looking into the sensors now, just throwing me for a loop no check engine lights at all

Like OBD I, for a ford with a code 11-10-11 if it links up and gets a pass code, it just has inability to rat on itself. That leads to diagnosis by symptom. mitchell database has sensor parameters but update them all, and use Crown, that's best and lasts without intermittancies and engine dying, right? loose connector fit was a problem, like socks on a rooster.