guidon112

Help me out; I am completely stupid when it comes to emissions equipment. I don't want to know how any of it works, all I want to know is what malfunction or malfunctions will cause a cat to glow bright red. I planned on removing the old school air pump and cat, and putting in a Y pipe, but when I went to go for a test drive today, my beast did not idle smooth, like it did Thursday after I put the new fuel dizzy in, it would not rev either, and after a few minutes of rough idle, I noticed smoke from below. I looked under the car and the cat was bright (and I mean BRIGHT) red. What causes this to happen? I have never in 30 years of wrenching seen anything like that. Could it be because I always remove emissions junk from my older cars?

mcholdfast

Dumping unburnt fuel into a cat will cause it to glow red. I had the same problem with a VW Corrado and it turned out to be a bad coil.

123quattro

You probably had one cylinder loose spark. That extra fuel combusted in the cat. Now it's most likely melted and will need to be replaced. They become huge restrictions when the substrate melts and turns into a big piece of modern art.

guidon112

Ok so one possibility is that I am still running too rich. That is a likely situation because Thursday I may have been running smooth on a strong dose of fuel system cleaner, and today I have fresh new fuel, because while I was working the fuel problems (finished Thursday) I ran out all the old fuel+chemtool mix that was in the tank, and today I put in 5 gals of fresh premium. I will lean it out tomorrow and see what happens, thanks.

I'm still going to trash the old emissions junk.

guidon112

Ok so possibility number two, but Thursday it was smooth and strong revs to 5k in an instant, and 900 rpm steady idle. It sat all weekend though because I had to work. Thanks

guidon112

Leaning it out did the trick. sprung a new vacuum leak while I was tinkering, gonna track that down tonight, I "WILL" have this beast on the road this week, or I will die trying. Crap late for work