Catalytic Converter glowing Cherry Red
Senior Member
Joined: Mar 2014
Posts: 952
Likes: 55
From: Eastern Long Island, NY
Year: 1996
Model: Cherokee
Engine: I6 Cyl / 4L
What year Jeep? How many miles on the cat?
How's your Jeep running?
I read somewhere that it could also be your fuel mix having too much fuel and that is cooking your cat.
Are you getting any codes?
How's your Jeep running?
I read somewhere that it could also be your fuel mix having too much fuel and that is cooking your cat.
Are you getting any codes?
CF Veteran

Joined: Apr 2016
Posts: 1,820
Likes: 60
From: Pasquotank, NC
Year: 1990
Model: Cherokee
Engine: 4.0
In my experience, it is running rich. The catalytic converter burns off unburnt fuel and certain exhaust gases to make them less detrimental to the environment. If you introduce too much fuel to the exhaust, it will overwork the cat. What does your oil smell like? If it smells strongly of fuel, that also points to running rich.
Senior Member
Joined: Nov 2014
Posts: 766
Likes: 5
From: Los Angeles, CA
Year: 1989 Limited
Model: Cherokee(XJ)
Engine: I-6 4.0L AMC Renix
do you have a picture of your cat? Sounds like a sight to see. But I agree with checking for codes, fuel mixture (to rich or lean), and also try tapping on your cat with a rubber mallet while it's cool and listen for jingling. If it's jingling, get a new one, if it's not, definitely an issue further up the line.
If its glowing cherry red, id say the damage has been done. The substrate inside overheats and evntually melts, literally. Once it starts, there is no turning back. It will clog which can lead to hard starts, no starts, stalling and loss of power on hills. Worn out cat, o2 sensor, injector, temp sensor, fuel pressure...could be anything.
If you think you smell gas in the oil, DO NOT wave an open flame or use a lighter over the filler. If it goes, losing your eyebrows will be the least of your worries.
This is a cat gone bad. Vehicles have caught fire because of this.
If you think you smell gas in the oil, DO NOT wave an open flame or use a lighter over the filler. If it goes, losing your eyebrows will be the least of your worries.
This is a cat gone bad. Vehicles have caught fire because of this.
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CF Veteran




Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Yep. Etiher running too rich, or hte cat is bad, but.... the cat is bad if it's running like that.
Don't just replace the cat. Find out how it got that way or you'll be replacing it again.
And yes, that's a catastrophic fire waiting to happen. Do not ignore this.
Don't just replace the cat. Find out how it got that way or you'll be replacing it again.
And yes, that's a catastrophic fire waiting to happen. Do not ignore this.
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors



