Glowing exhaust manifold on 2000 TJ 2.5

[SSTJ]

Have you made any progress on this?

Nope, changed the cylinder 4 spark plug, cleaned the spark plug wire. Cleaned the idle control valve, tps, and map sensor. Nothing yet has really changed anything. At first I cleaned the sensor with carb cleaner, then it drove worse, went back and cleaned with maf sensor cleaner and it’s a little better. I think the misfire is still there. I don’t have enough right now to replace every sensor so I’m guessing on which (if any could be causing the misfire). I have not replaced the 02 sensor yet. Maybe that is it. The code I get is bank 1 sensor 1.

I'm not sure, but I think that is the code for the upstream O2 sensor, right by the top of the down-pipe, where it meets the manifold.

I still think this sounds like an easy next step. Given the error code you got, and given that @Jerry Bransford recommended the O2 sensor on that other thread that you bumped, and given that it's so cheap and easy to swap out, this might be worth checking off the list before anything else.