Cherry-red exhaust

[MA-XJ]

Help! I was driving last night, when engine began running very
rough on acceleration. I thought that maybe I could make it home,
but it got worse, and I pulled over. When I stopped, smoke was coming from under jeep, and when I looked under jeep, the exhaust was red hot, Between muffler and cat. A friend told me engine is running lean,
does this sound accurate, and how can I fix it? Thank you.

[thinmints]

Sounds like your cat is plugged up i would take it to a muffler shop and have them test it for you

[MA-XJ]

OK, thats what I thought it might be, so when I pulled in to a rest area, I actually pulled off my cat.
This did not help at all. (Sorry that I forgot to say
that I did that). Also, my Cherokee is a 1992, with
167,000 miles on it.

[MagicRat]

Your engine is likely not burning the fuel properly. I suspect an ignition problem. Its either missing on a cylinder or two, or the ignition timing is retarded.
Since the timing is electronically controlled, I think the engine is missing. It has nothing to do with a plugged cat.

[Ironic]

I would lean towards O2 sensor, or throttle body. Lean fuel mixture would cause this.

[GdWrnch2001]

My lumina did the same thing last year. The problem was the injectors were BAD. They were sticking open allowing TOO much fuel at low rpms which inturn ran rough. Did your jeep run good at high RPM's? I take it your jeep is TBI. Pull the injectors (2) and do an Ohm's test on them. The reading should be 12.4 or higher if the reading is lower they need replaced. Change the plugs also.

[MA-XJ]

I will change plugs, (maybe wires),O2 sensor, then check resistance of injectors, and see if this helps.
Thanks for all replies.

[MA-XJ]

My jeep XJ is still not running good. I changed plugs,cap,wires,rotor,
O2 sensor, MAP sensor,checked resistance of injectors (all OK). I still
need suggestions of what to do next. Right now, I can not afford to take it to a repair garage to have it checked out.