What does the process. Is it simple, can I do it myself. Basically what is involved and what gains will I see with that with my cutout?

 

You remove the cat and there is a lot of honeycomb material inside. You get a pipe and punch out all the honeycomb material and then reinstall.

With a cutout you will get amazing flow for great top end. Really lets the car breath. Your exhaust will sound terrible most likely (some people will disagree) and your torque level will go way up so you won't have any low end torque.

I would recommend gutting the cat unless you have ram air or a cold air intake. You should have headers as well but a gutted cat will sound especially bad with headers.

 

A cut-out is defentily worth the money. Great mod for the money!

 

One question norcalstreet, what about Smog Tests (inspections) ?? With a gutted cats, then your car will fail the smog test... I would recommend gutting the cats, if you live in a state that does not require Smog Tests... Otherwise you are running the risk of getting Fines and Jail Time (especially since California has one of the toughest Smog Laws)...

Charlie

 

Thanks for the replies, but Im more concerned about the process than the gains. The gains will come when its all done. If anyone has done it I would like to know what is involved. Does it require welding or is it a simple bolton setup. I do not want to gut the cats as then I would not pass emissions. I would like to keep them in the garage and put them on for the tests only. So pretty much what im asking is can i just remove the cats and bolt the exhaust pipe back up to where the cat was or is it more complex than that?

Thanks in advance.

 

dfintly not that easy...u need to get offroad pipes to go in place of where your cats would be and have to have them on flange clamps....which will cost some money

if you really want something tht is worth the money and a switchable cat...get flp longtube headers...u can take the cats on and off in a matter of minutes

 

Yes, you will fail.

 

not here in chicago where blacko1z is at....

we have testing for obd2 where they just see if you are throwing codes and you are good

i passed emisisons with my offroad pipes on

and there are cars here that pass with heads and cam and strokers...so it depends on where you are located....

your in cali and i know its tough over there with emmisions

 

Check around ... One of the guys in our club just did a full exhaust .. headers to tips! He gave away his stock exhaust system since it was going out in the trash.

I got his cats for free and gutted them yesterday afternoon. It took about 30 minutes to do it completely (removed EVERYTHING from inside both cats, not even any of that cloth stuff left in there)

Now I've got a gutted set, and will have my stock set as well. Once I get some O2 sims, I'll put the gutted set on the car.

There are a few folks in the club that pass emmissions with gutted cats in their LS1 cars. If mine doesn't pass, I'll put my stock cats back on and go through again.

So, it just depends on where you live and how strict their emissions laws are.

But ... see if someone has a set of cats left after doing their exhaust.

 

So what your saying is when I eventually get headers just take the cats off at that point.. At the moment my exhaust with the exception of the cutout just after the cats and chrome tips is stock.

So essentially I will be running a set of FLPs to a cutout.
Yay! even more reason for my neighbors to hate my car!

And I thought my Z28 was loud when I bought it stock, lol boy did the cutout change my view on that.

 

You know what guys, I'll tell you this much, I run gutted cats and borla catback half open and it sounds badass, believe me. Who ever said that a car without cats sounds bad is wrong, it sounds sweet, just louder.
And the gains are pretty much nice especially on top end, low end is a little worse than with cats, its noticable. The good part is that 2000 up F-Bodies use bolt on cats.

 

Would some aftermarket high flow cats be a good substitution for gutted ones that will never pass those Cally emissions?