I have 1991 f150 4x4 302, I hollowed out the rear cat about a year ago but i am now having a problem (maybe) with the front cat. After taking her for a ride I noticed the cat was really hot, to the point where it was slightly red at the rear end of it.

I also noticed that the AIR pipe had rotted off and was hanging there.

Is the cat on its way out? and where can I get the small apadtor pipe that connects the AIR pipe the little nipple coming up off the exhaust pipe?

thanks for you help.

 

sounds to me like you have a plugged cat. Or you are running real rich to the point where you have gas coming out of the cylenders and then exploding in the cat . I have seen this on a jeep but it was way out of time, and due to the bad timing it was firing after the exhaust valve opened and let the gas out. The cat got cherry red. If you do this too much you will melt down the cat and plug the exhaust. Does it seem like you have a power loss? Dont worry about the air pipe. All it does is blow clean oxygen air into the exhaust to help the rear cat work bette. The catalitic process works better with the presence of oxygen. I would take off the air pump or just pinch off the hose. Then plug the hole in the exhaust pipe. I would just cut off the front cat and replace it with a Y pipe.