Thread: 99 GTP runs fine cold, seems to lose a cylinder when up to temp?

Originally Posted by gtpinsc

drive the car at night... look under the car when u get done, somewhere where there isnt much light and see if the cat is glowing.

OK, will do BUT if it is a clogged/bad cat, wouldn't it run ****ty right off the start? Wouldn't the excess backpressure affect the entire engine as opposed to just the rear bank? Does the flow of exhaust become increasingly impeded as the cat rises in tempurature?

I'm in no way dismissing your theory gtpinsc, I appreciate your feedback man, I've got an infrared thermometer, I'll take a reading of the cat as soon as I shut her down when I get home from work tomorrow...