I have heard this and dont know if its true. I have a buddy that has a 94 camaro, he bought it from his cousin. the car had no cat on it. he decided to have it rebuild, and the guy that rebuild it said that his valves were fryed and he said it was because that it had no cat and therefore wasnt putting back pressure back into the engine, is this true or is it a mith

 

False for sure.

 

please has anyone else heard of this, and nice camaro by the way

 

100%

 

hey i dont know if this helps but i have a 93 Mercury Cougar XR-7 and i busted the heads about 4 months after i bought it...the guy that rebuild the heads told me that it happened because i had no exhaust on it....basically i hacked the exhaust from the cat back....well the cat too....anyways...he said that because there was no back pressure that that was why the heads busted....what do i think professional racers run straight pipes without cats...i mean i have seen many guys build cars with pipes for each cylinger shot straight up and thats how they run it...do me personally...thats a myth....so just do it... ... everyone i

 

On a speed density system, reducing the factory assumed back pressure can lead to lean running if severe enough, and if not reprogrammed may do some sort of harm. The biggest harm is to the way it runs. Unleaded fuel compatible exhaust valves and seats are pretty hard to hurt, though, so the likelihood of reduced backpressure causing valve damage, without any other contributing conditions, is very remote.

IIRC, 4th gen V6's were MAF.