i would start by checking the cat if you hit it and here stuff rattling around in it change it. Then if that is not your problem when the problem occurs check for spark at the cylinder that is missing. If it has spark then you will want check the injector to make sure it is pulsing to do this you need a noid light can be had at most tool or parts stores. But as for the hot exhaust pipe that sounds like it is running lean maybe a clogged fuel injector or clogged fuel rail.

 

I think it might be the netural safty switch, it fits the bill it controls alot of the 00 and 01 cherokees.

cleaned the terminals and is running better, but still has a check engin light. It is around $300 to replace it

On jpmagazing.com I found an article that explains how to rebuild it for around $5 , and it decribs all thhe symptons that my jeep is haveing hope it works