Hello,
I finally finished retiming my 91 Civic DX (1.5L 16V) and as I had the engine idling in my driveway, I noticed that the cat was glowing red. I'm assuming that this is a sign that the engine is running rich. I don't get any check engine lights or anything abnormal. The engine stumbles a bit taking off, but seems to run fine. What could be causing this?
Thanks,
Mikel

 

Actually it might mean you are running lean because things start to get a lot hotter when you are running lean.

 

Maybe the cat is clogged and the excessive exhaust pressure is causing it to glow red. There was a car where i suspected that the cat was clogged, the exhaust manifolds glowed red after a couple of min of idling.

 

how long does it take for the cat to start glowing?

 

If the cat is glowing then it is ruined, something probably broke inside and it is clogging the flow through the exhaust system.

 

^^^ what he said is usually the cause.

 

Agree - clogged

 

get out the drill, hollow that bitch out.

 

Thank you all

 

If you hollow the cat out then it won't work. Then you fail emissions.