Anybody have an OBD 2 LS with a Drag kit on it? If so and you have gotten rid of the stock cat which test pipe or hi-flo cat did you use. How much of an increase did you get?

I think that my cat is holding me back - before I turboed my car I put a Apexi N1 cat back on it and the exhaust didn't get much louder then stock, my brother put a HKS catback on his SOHC Civic and it roars!! WTF

 

ttt

 

Come on somebody has to have some sort of advice

 

hi flow cat

 

a stock cat will always hold u back. i recommend a testpipe from http://www.testpipe.com (i just got one and put it in last nite, pretty decent piece). Make sure u specify ur model year when ordering. About the sound... it's pretty much all in the muffler, and remember... loudness isn't always a good measure of power

 

Well, an Apexi N1 isn't exactly a quiet exhaust...could it be possible that my cat is clogged, I get a little compressor surge too! I don't want to throw codes do they have a test pipe that will work with OBD2 - Typically I have found that and exhaust will help to open up the engine, this didn't help open up anything, sounds the same even with turbo as it did stock basically - not exactly I mean it is a little louder but not much, not much at all - I was very surprised as to how quiet it was!

 

Added back pressure of the turbo quiets the exhaust. Also, being OBDII you have a few options:

1. Convert from OBDII to OBDI and get a test pipe.
2. Buy an ECG O2 simulator from importparts.com and get a test pipe.
3. Get a high flow cat.

 

Sure the backpressue deal with turbo I understand that, but before I boosted the car I had the exhaust and it was still very very quiet! What are the symptoms of a clogged cat?

 

ttt

 

Every obd2 car ive ever put a test-pipe on throws a cel. The primary 02 and secodary 02 have to have a slightly different reading. Using a straight pipe doesnt allow for that. Best bet is to put the ecg o2 sim. and your set.

 

Ok then if I put the ECG o2 simulator on it would I need to worry about buying a "test pipe" with a bung in it, or could I just have the cat removed and then run straight pipe from the turbo back? (no bung)

 

Yes, with the O2SIM you will no longer need a bung on the test-pipe. The second O2 sensor can be totally removed.