well, i just got one of my precats gutted, the other seems to be just a resonator. Im wondering if i should gut my main cat, cause smoke is still commin out of it. think it could be clogged, and I can't seem to pass cali smog anyways. But im being hesitant to. How much louder would it be? And would it mess with my 5th and 6th ports? I got an series 5, 1991 N/A.

 

um.. there is NO way (short of an exchange of excessive amounts of cash) that you're going to pass cali emmissions with no cat..

 

s5 5 and 6's are operated by the air pump not back pressure

 

1st...simply gutting your cats is rice and is no where near as effective as a propper exhaust.

2nd...no chance of passing inspection.

3rd...catalytic converters do not "smoke". Your smoke is coming from your engine.

 

Well you could gut your main cat, but it will sound strange and when it backfires it will sound like it is doing it in the cat. I did notice a power increase when I did it though. Or you could go to a muffler shop and get a 17" piece of tubing and have them weld two exhaust flanges flush to the ends. Thus a cat replacement pipe. This made the sound much better. Plus now I can shoot flames out the back.

 

my cat turned out to be gutted ..the precats too!..That my friend,was why I did not pass emissions..the owner before me failed too!! .He didn't know about it either!.If it's for emissions testing ,have good functional cat on the car ..you can buy a look alike ..gut it .buy a presilencer ..anything..AFTER you go through(if you are doin the legal way)..my $.02

 

I would buy a good, used stock cat for passing emissions. And I would also recommend gutting your (old) main cat, because it's easy and there's about 10-15 hp to be gained by doing so.

I had gutted cats and a TII cat-back on my s4 N/A (budget, baby!) and the power increase was very noticable and the sound was suprisingly good and agressive.

I'm not sure about any effect on your 5th and 6th ports by simply gutting the cats. Mine weren't working and instead of fixing/replacing them, I simply wired them open and called it good. Therefore I didn't have to worry about them functioning, lol.

On the other hand, if your 5th/6th ports ARE working, do ALL that you can to maintain their functionality ...

 

im not too worried about emissions, as i stated before, my car won't pass with a working cat anyways. And since its sort of clogged up, i thought i'd mind as well gut it. But what im worrying about is the 5th and 6th port. I got an s5, which uses the air pump, so it dosn't affect my ports if i gutted it right? Thanks.

 

just get a race pipe. the only reason to gut a cat is so that it at least appears that you haven't tampered with it.

 

^^^

Or because you're poor and don't want to spend money on a race pipe. Gutted cats may not be the absolute best solution, but it's cheap and effective.

 

hmmm, just wonderin. Is there a way to fit a pipe inside the cat after its gutted to decrease turbulance? And it shouldn't affect my aux ports right? Just making sure.

 

curious..do you have to pass emissions?..if you do..suggest stock or high flo cat..i had a hollow cat on mine..and it did not pass.period...the cat has a pipe that comes off of it and uses the back pressure to activate your aux ports..so if you hollow it out keep the pipe connected to it..my aux ports worked fine with the hollow cat..if you go the test pipe route you will have to contend with the port situation too..my $.02..again

 

keep it. go have a shop do up a straight pipe the same length. ya never know when youll need it again. how sure are you its clogged?

 

listen to a car with a race pipe before you put one in, just to make sure you like the sound...it doesn't really sound like you would expect it (not to me anyway) and you may or may not like it.

 

It's retarded loud....especially if you have a setup like mine...RB 2.5 DP, gutted cat, single N1 knockoff...

A bunch of people here that have heard my car can vouch for this one lol

 

Mine was suprisingly quiet with the stock TII cat-back and gutted cats...

Sounded great (and not too loud at WOT).

The resonators/restrictive stock DP/Cat. setup do a lot to help muffle the sound.

 

well, i gutted it and i was happy with the results. The sound was deeper, a lil louder. I got a short sound clip or vid clip of it if anyone wants to hear it.
It smokes and back fires everytime i hit 7k or higher and let go though, hopefully my RB exhaust can handle it.

 

This kinda stuff is what gets car guys bad names and reputations. If its a rcae car and not used very much and def not on the roads then by all means get a test pipe (cat eliminator). But if you drive the car on the road why dont you not be a douche and just buy a high flow cat fomr summit. The cat itself is only 50 or so bucks. The pipe to make it work would be cheap and if you aren't good with a welder a mufler shop could get you legal for very little money. If you drive that car on the street and get pulled over you are gonna be effed in the A by some cop. Your car might get impounded to. The fine you would get would be like atleast twice as much as being legal.

I got my car smogged here in AZ tonight and it passed with flying colors. We all live on the earth and every one persons contirbution to the environment be it good or bad makes a difference.

 

aww, im sorry to give you guys a bad name, but this is just temporarly. So i guess I'll continue being a "douche".
like I said, I was just askin because I was concern for the aux ports and the sound. The cat was clogged anyways. So I guess its gonna hurt the environment till I can afford a good cat.