94 Intrepid

My friend has a 3.5 and his catalytic converter keeps getting damaged about a week or two after a new one is installed. The dealership says it would take roughly $5,000 to get it running properly. Well I just am not sure about that. Any ideas?

It doesn't cost $5,000 to replace the cat. How exactly is it getting damaged, is the outside of it suffering from physical damage or is it plugging up where he has no power from the engine?

His cat is plugging from the inside, I know It isn't going to take $5,000 but the mechanic that looked at his car said he would have to run all these different kinds of checks to find the problem. I am sure considering it being the dealership you never know. lol. I priced the wiring harness for my 3.3 and it was $572 plus tax. I bought it for $45 at a salvage yard.

does your friend have a miss with his engine? If the engine's missing due to bad injectors, it can leak raw fuel into the exhaust and get caught up in the cats thus plugging them up. My first source of diagnosis would be those fuel injectors, it's not uncommon to have injectors leaking and sending fuel into the exhaust stream.

ok I will check, the o-rings are pretty cheap anyway. Is that common though for them to just start leaking though. If its not leaking at the injectors where else should I check?

does the engine run ok or is it sluggish and rough you could have a cyl missfire as the freakynasty sugested or you may have bad EGR valve making the engine run rich and damaging the cat and are you using chrysler cats or aftermarket may be the difference in size and quality and how long does the cat last and are you sure he is changing the same one every time as there is 3 cats on this vehicle

The engine is running rich, I am not sure which cat is being replaced, but I will have a look at it on sunday and give everyone a heads up. Thanks