View Full Version : Big mids no cats question

02-12-2005, 09:23 AM
Is there a disadvantage to not having the cats on the car? Such as using the mil eliminating device and big tubes w/crossover. Am curious. I do not have to pass emissions, just state inspection this month. Thanks.

John in Va. Beach

02-12-2005, 11:09 PM

I'm a bit new to this, and there are folks out there with a lot more experience than me, but the biggest downside with running with no Cats is:

1) emissions testing; since you don't have to worry about this, not really an issue, unless you move (save your old pipe).
2) you're a tree-hugger, and worried about the icebergs melting, which if you were, you wouldn't be considering no cats, and wouldn't have posted your question.
3) So therefore, considering "1" and "2" above are not your deals, then running with no cats gets you a bit more horsepower, and gets you bigger sound...

However, beware! Don't make my mistake; off-road x-pipe (no cats) and dual-chamber flowmasters don't work; sounds absolutely horrible. Combinations that do work are beyond my experience; I'm researching.


02-14-2005, 11:34 AM
That seems to be the case. I was just trying to figure out a downside. No emissions here, don't have a tree hugger on board, just want mo power. Thanks.

john in va beach

02-14-2005, 12:08 PM
Many folks have eliminated the o2 sensors without problems.
Technically, without the o2 sensors your car will not adjust the air/fuel
mixture as efficiently as it did with the sensors. Most aftermarket X-pipe
and H-pipes have two high flow cats instead of the four more resistrictive
stock cats. Also, even without the state emissions test it is illegal to
remove working cats from any street legal vehicle. This is a federal law not
a state law. I believe the fine starts at $1000 and goes up from there.
Having said that, I do not know of anyone who has been fined for removing
the cats of a vehicle. :D Thought you might want to know.