A cat flows 99% of a straight pipe. Do you have emmissions where you live? If so the answer is a no brainer.

 

my engine keeps coming on and off...i got it deleted and it came back on again...omg im going crazy

 

your engine?? or your Check Engine Light?

 

Might be running too lean.

 

I've got the XTC 2.5 WITH CAT... and the cat blew its insides out... and now I have no low end power without much improvement in Top End. I can't roll race from 35 anymore... 40+ only.

 

I went catless 3" down pipe. tolerable with stock cat back. now with full 3" it is way to loud but I have the right sound. oh and there is rattles and vibrations like crazy. cat will be in two days. wish I could do a before and after but no time on dyno is available.

 

I just want a sound clip!

 

OK I got it. Not promising anything but I will try to get a few for you.

 

Here' is a quick sound clip Vid of my Exhaust...

http://s138.photobucket.com/albums/q...0070828008.flv

GMPP Performance, XTC 2.5" with EMPTY cat, and GMPP Header.

Here's a Fly-by:

http://s138.photobucket.com/albums/q...Fly-Bys002.flv

And another:

http://s138.photobucket.com/albums/q...Fly-Bys003.flv

 

I just got my 3" in and out Cat. my exhaust is

- ZZP shorty header ceramic
- ZZP Catless DP
- Catylitic 3" in and out
- custom cat back with resonator and flo-pro muffler
this a full 3" system

I have a clip of it without cat. will post both without and with cat. let me tell you in car experience is the biggest part. cruising I have eliminated 95% of resonance. the experience can not come through on video tape cause you wont feel it on your chest....LOL. If your going 3" and it is a daily driver I totally recommend this system with cat. it is borderline tolerable. and I am ok with a loud exhaust system.

now I am ready for motor mods. next is cam's, cam gears, valve springs, port and polish everthing (head, intake and SC).
Then 10:1 pistons.

other than LSD and coil overs the car will be done IMO. should be close to 400HP at crank when done I hope.

immidiate need is an HE for intercooler.

 

I just installed my catless DP a few hours ago from zzp.
and so far im very happy.
I love the throttle response, the engine wants to rev alot more freely, especially at low RPM.
theres buttdyno increase, and i love the new tone.

all in all im very happy with it

 

so your not supposed to go WOT with a new high flow cat for 250 miles?

 

Dude I wish I had that road where I live, I'd be up and down it all day working on 1/4 times.

 

correct

 

I thought it was longer! I clogged mine,then went with it gutted which was better anyways.

 

Your going to have a CEL regardless, just so you know. I went with the high flow cat just to tone down the sound, and I'm glad I did cause I'm still trying to tone down the sound.

 

i got a CEL when doing this,turned it off and it never came back

 

yeah i can clear CELs with my dashhawk, and if it keeps coming back ill just have a buddy take care of it with HPT

 

ok thanks guys, CEL's won't be a problem, i can get that taken care of

 

How about a kit that allowed you to tone it down and then with an allen key you can remove the kit and have more flow for track days or a night of fun? I am working on it.

lol

funny I just got a cell today.

 

catless

 

no catted

 

and why if you don't have emmisions its worthless. and if you went we a cti header like me you get 2 dp's one catless the other catted

 

That would be dumb IMO.

 

nope depends on what you want