Hey! I’m trying to diagnose a rough idle issue on my girlfriends 2000 Cherokee Sport 4.0. It seems very random. It doesn’t seem to be affected by weather and hasn’t thrown any codes. When it’s really bad, the Jeep will stall at red lights and stop signs. It then requires some footwork on the throttle to start and keep it running. Everything feels great when not idling. Other days, it has no issues at all.

Here’s what we’ve done:
- New plugs/wires
- Crank sensor
- MAP sensor
- Fuel pressure test (47 psi running, though the Jeep was running well when I tested)
- Cleaned out Idle Air Control Valve

The last two ideas I have are O2 sensors and timing belt. I don’t know much about cars, so there’s probably something I’m missing here. Looking for some input. Below are pictures of a test I ran today with a Bosch scanner, of course the Jeep wasn’t acting up when I took it in, but I’m hoping these results might have a clue (I don’t know how to interpret them).




This is the same screen as the photo above, but shows how some lines are fluctuating.

 

There’s 4 02 sensors on the CAT. They can cause the jeep to run ****ty while idling and stall. It’s odd one of those codes isn’t up when u scan it though.