What would cause a cat to glow red?

 

extreme heat...

i'm talking 1K+ here

 

I wonder if your cat might be clogged? you might want to check that out because if it is your motor will be at serious risk.

 

I agree with ChuckZ28. May be a clogged cat. Have you been experiencing a loss of power lately. This will also be a symptom.

 

Running Really rich, clogged cat are the two things that come to my mind.

 

Are your manifolds/headers glowing as well? If not I would say clogged cat.

 

Are your headers/manifolds glowing red as well? If not I would say clogged cat.

 

Sounds really dangerous.Please get this checked asap.My02

 

Haha! LMFAO!

 

Usually a glowing cat means both excessive air and fuel present in the exhaust. If the engine is simply running rich, it will actually cool the cat(s) and if it's running lean it still won't experience such elevated temps. Most probable cause for such a condition is an exhaust leak or an ignition problem.

If it is a "clogged" cat you will lose performance, many times the cat will rattle when tapped, and sometimes you will actually here it hiss under heavy load. Many times the cat will clog because of failure related to the conditions above. If it is simply replaced without fixing the underlying problem it will meltdown all over again.