lsejnoha

So the shop here in Denver got my 951 up and running and supposedly knocked out the internals on my catalytic converter. Supposedly the cat was clogged and thats why my car would not start. What a f!@#$!ing pain in the *** that was trying to figure out. So now i am super excited to be getting my baby back but there are still many things with this car that need to be addressed to make her perfect. But I am wondering if they knocked out the internals in my cat shouldn't I notice a slight power increase. I heard if you delete the cat you can get a pretty decent boost sometimes, conceivably around 20 to 30 horses even. Does anyone know if this is true.

Willard Bridgham 3

Depending upon how bad your cat was, the pressure drop could be in the range of 5-10 psi. Convert that to hp.

CO951

I too run a gutted cat here in Denver. You should see some increase, but not as much as with a proper straight pipe exhaust. Running your exhaust into the chamber the cat was in allows it to expand, but then has to compress again to get out, this creates some back pressure. The benefit is it will pass the visual inspection for emissions, if you can get the rest of it to run clean enough to pass (which is possible).

KevinGross

You get zero HP from gutting the cat on a stock engine. They are sized by the factory to flow without knocking down power. If you've changed the engine, chips, etc, things could be different.

ekoz

I had gutted cat and autothority chips and car made good power, I believe I had 250 WHP back then. I even passed a tail pipe emissions without a cat one time.
I agree with Kevin....without other mods small to no gains.