no cats?

**archer3728** · 02-17-2010, 07:24 PM

im thinking of getting some flexible exhaust piping to replace the cats what size pipes would they be its pretty much stock exhaust w/ a cut out

also what are the prros and cons of this set up?

**0rion** · 02-17-2010, 07:29 PM

that flexible stuff isn't going to last very long....it's just not meant to be a permanent pipe. You'd be better off cutting a piece of solid pipe and using some reducers and clamps. It'd last much longer. Actually, if you know someone that'll weld it up just have the pipe welded in place.

**Dr.Crash** · 02-17-2010, 08:29 PM

since you live in california smog is an issue. but if you dont mind changing it out ever two years then just do like orion said and weld in some solid pipe. Just pull your cats out and measure them, then go to a muffler shop and ask for two pieces that long. in cali they wont weld them in for you at the shop unless you know someone or you tow the car off their lot. kinda a bummer. but i think worth it. What else do you have done to our car?

**archer3728** · 02-18-2010, 05:28 PM

also i know it will throw a code but will not having the cats making it run differently and if it does does any one know how to make o2 simulators?
my mods are ls6 intake, ported and polished tb, slp intake,posi rear end, ported and polished heads, and a ls6 cam

**cammed goat** · 02-18-2010, 06:18 PM

Check our sponsors as I am sure they sell O2 sims. Also, you might want to look into a tune to keep the SES light from coming on and you getting teary-eyed from the raw fuel odor you will inhale at a stop.

**archer3728** · 02-18-2010, 06:33 PM

so of i dont tune it out will i lose power?

**cammed goat** · 02-18-2010, 06:43 PM

Originally Posted by archer3728

so of i dont tune it out will i lose power?

You won't lose power. You will have an SES light and your car will smell to high heaven at stopsigns/lights.

**Smittro** · 02-18-2010, 06:48 PM

Originally Posted by 0rion

that flexible stuff isn't going to last very long....it's just not meant to be a permanent pipe. You'd be better off cutting a piece of solid pipe and using some reducers and clamps. It'd last much longer. Actually, if you know someone that'll weld it up just have the pipe welded in place.

This...

Flex pipe will only last as long as it holds back water. Condensation will build in that setup for sure and rot it out quick. Short trips say 1 to 3 miles creates a poop ton of water in the E-pipes.. Imho I would reconsider even using it. Here in PA. we have more lax laws about smog, but here flex pipe is illegal on passenger cars/trucks.. I honestly don't see it even passing on the left coast..

**archer3728** · 02-18-2010, 06:55 PM

Originally Posted by cammed goat

You won't lose power. You will have an SES light and your car will smell to high heaven at stopsigns/lights.

you think id get worse mpgs?

**cammed goat** · 02-18-2010, 07:10 PM

Originally Posted by archer3728

you think id get worse mpgs?

It's possible. I have seen threads about cat efficiency codes being thrown due to lack of cats.

**ramtough9** · 02-18-2010, 07:53 PM

So do the LS1 motors need to have the cats on them for HP production or can you get away with removing them and then tuning out the O2 sensors?

**Dr.Crash** · 02-18-2010, 07:56 PM

You don't need cats, 02 sims or tune out

**archer3728** · 02-19-2010, 01:36 PM

alright i got another question

if i just gut the cats and put some 02 sims will it still pass smog?

**KahanaReef** · 02-19-2010, 01:55 PM

No, it won't pass smog with gutted cats. If you're going to drive it on the street, you're gonna have to pass smog. Of course, if you know someone...

Are you wanting to go with just the stock manifolds and remove the cats?

**archer3728** · 02-19-2010, 03:08 PM

ya stock manifold w/o cats

**KahanaReef** · 02-19-2010, 03:10 PM

Any particular reason why?

**archer3728** · 02-19-2010, 07:56 PM

mo powa, and my girl gets all horny with louder cars

**Skippy** · 02-19-2010, 08:51 PM

Ive never heard of any good luck with O2 sims. On my car I tried a cheap little experiment with a pair of spark plug anti-fowlers that I picked up at advance auto parts. You take the pair of them, drill the opening of one of them out to 5/8 and leave the other alone. You thread the O2 into the drilled one, thread that one into the un drilled one and then thread that into the cars exhaust. I have them on my DD and ive put about 4K on that setup and have not had a single problem. Fuel mileage hasnt changed, no ses light, no probs. at all. This was my temporary fix until I get a cam and then ill have it tuned for both cam and long tubes.