Cat vs No Cat

bmoyce

SDD Junior Member
Joined
May 16, 2006
Messages
12
Reaction score
0
Location
Redwood City Ca
I'm a dog man.... Lose the kitty! Sounds great, noticable power increase, about 1 mpg increase(for me) and only one nice puff of smoke with a good spanking from the skinny pedal.
Side note... I put a 4" system on mine and went back to the stock 3.5" no kitty no muff. Runs way better in my opinion (mpg @ hp)
 

kenholl

Its my side of the garage
Joined
Oct 1, 2007
Messages
275
Reaction score
0
Location
McKinney, TX
My exhaust has been stock since I bought the truck a year ago. Last weekend I pulled the sleeve off from between the cat and muffler, basically leaving me without a muffler. A couple of things I noticed...

  • I have not yet noticed any difference in milage, which tells me the muffler didn't hurt it.
  • The exhaust sound is noticably louder
  • When I start the engine, it sounds loud and throaty until the cat loads up with pressure, then the sound chokes way down

It is clear that the cat creates serious back pressure
 

dennisj2003

Full Access Member
Joined
Jan 9, 2008
Messages
144
Reaction score
0
Location
Lizemores/WV
My exhaust has been stock since I bought the truck a year ago. Last weekend I pulled the sleeve off from between the cat and muffler, basically leaving me without a muffler. A couple of things I noticed...

  • I have not yet noticed any difference in milage, which tells me the muffler didn't hurt it.
  • The exhaust sound is noticably louder
  • When I start the engine, it sounds loud and throaty until the cat loads up with pressure, then the sound chokes way down

It is clear that the cat creates serious back pressure


The 04s and up will be a little louder at start up then get quiet as the vgt closes up to run the egr system, and will only be loud when you fuel it when the vains in the turbo open.

I took mine loose at the down pipe and run around town a few laps at wot it sounds like all h3ll breaks loose but at idle is as quiet as if it had a muffler.
 

Good Enough

SDD Junior Member
Joined
Nov 3, 2008
Messages
10
Reaction score
0
Location
Norfolk, VA
Generally with a force induction vehicle the less restriction you have on the exhaust side the better your spool will be on your turbo.

I have an SRT-4 with turbo WAY bigger than stock so spool is a big thing with me. If i could get away with just running a down pipe i would.
 

Sawboy

Full Access Member
Joined
Jan 25, 2007
Messages
190
Reaction score
0
Location
Westchester IL
I am in the same boat as most others. I noticed about 1 mpg gain, and the sound is MUCH better overall, and the whine is slightly louder.
 

Work&Play

SDD Junior Member
Joined
May 22, 2008
Messages
6
Reaction score
0
Location
CT
Has anyone just gutted the cat? I have a 07 with a 4" turbo back and was thinking of gutting the cat so if they look it is still their. How hard is gutting the cat?
 

sawed off

Party like a rockstar
Joined
May 29, 2007
Messages
131
Reaction score
0
Location
EGF MN
does the cat come off easy? Im sorry for the bonehead question guys
 

DaveBen

SDD Senior Member
Joined
May 31, 2005
Messages
9,629
Reaction score
81
Location
Ukiah, California
It is not hard. Take a pipe and jamb it into the cat and remove everything. Get it all or it will rattle. That is an expensive cat to be destroying. Get a test pipe and replace the cat with that. KEEP THE CAT. You will need it sooner than later.

Dave
 

sawed off

Party like a rockstar
Joined
May 29, 2007
Messages
131
Reaction score
0
Location
EGF MN
It is not hard. Take a pipe and jamb it into the cat and remove everything. Get it all or it will rattle. That is an expensive cat to be destroying. Get a test pipe and replace the cat with that. KEEP THE CAT. You will need it sooner than later.

Dave

can i just use a test pipe instead of wrecking the cat? and does it come off easy? or is it a couple clamps holding it on. Thanks for the response!
 

Members online

Forum statistics

Threads
30,545
Messages
266,136
Members
14,673
Latest member
Doms350
Top