Most of the header bolts backed out a while back and I drove it for several months with the exhaust leak. I got new O2 sensors which were bad but was the cat affected in any way? I heard it could melt with an exhaust leak. Car runs very well but I am failing smog and am curious if I should swap the cat.

Thanks

 

Eventually, yes it will.

Mine became clogged after running with an exhaust leak for a long enough time.

 

Did you hear kind of a high pitched sound from the header leak? Like was it a higher pitched scraping sound? I'm just curious.

 

I really dont see how a leak could ruin the cat but im in a non smog state , so im not really to knowagable on cats.

 

I believe the theory would be that the car would run richer and the soot would plug it up. I don't know if i really believe that. I ran my heads and cam car with a cat for several years and it never really plugged up. It was running pretty rich at idle with no air pump either.

 

Hmm, I guess you could call it that. I'd say it was more like a slapping sound in the engine creating a very loud, noticably unhealthy engine. Kinda like having a cutout at the block.

I am not passing smog and I have a Carsound hi-flow cat. Some say that this is my problem. I thought maybe the exhaust leak made the cat even more of a problem and that if I swap it for a new one it might make a difference.