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Discussion Starter #1 (Edited)
This morning I elected to do this mod, which took about 90 minutes total. For those of you with smog inspections, who do not like taking on/off your CAT with a delete pipe, and who would like to save a $100.00 for the delete pipe, this mod is for you.

1: Remove the four flange bolts/nuts holding your CAT to the rest of your exhaust system. In my case, I have a DPF delete pipe.

2: Loosen and remove the band clamp that holds the CAT and down pipe together. Use caution, so the CAT pipe doesn't bump you in the head.

3: Previously, I had removed a transmission bracket that holds the CAT in place. I removed this, so the CAT can be removed. Just rotate the CAT and it will drop right out.

4: Using a hammer and a 18" breaker bar, I pounded the honeycomb crap out of the CAT. Once you punch a hole into it, the rest will easily break up and fall out. You won't believe the crap that comes out. I can't believe the exhaust can flow through that honeycomb stuff.

5: I elected to wash my CAT inside and out, which cleaned out all the black soot. I used some Aluminum wheel cleaner, which made the CAT look brand new.

6: Re-install your CAT and enjoy.
 

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That's the shit that came out?!?! Wow that is amazing it flows through there!

And that's a pry bar not a breaker bar lol sorry I had to
 

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Discussion Starter #3
I know.....I was fricking stunned my truck could still run with that crap in there...lol.
 

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problly over 150 bucks in platnum laying right there..lol
 

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I am curious if you can notice the performance difference, after the modification.
 

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Slave to the Interwebs
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I had a Tahoe I gutted the cat on. The exhaust sounded funny afterwards. Is there any change in the exhaust note?
 

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I did mine in about 40 minutes, just unbolted the rear flange, popped the rubber hangers off the muffler/pipe and used a long 1" spade bit to chew out most of the "stuff" followed by a pry bar and vacuum cleaner, then I started it up, blew out a bunch of "stuff" and reconnected the exhaust pipe and hangers. A little brake fluid helps to get the hangers back on.....
 

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Hot Rod Photographer
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Did it on my old superduty.. The tone changed a little.. Thank god I dont have that 6.slow anymore.. What a piece of crap that truck was..

Yes the tone changes more "flow noise"
 

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I have gutted several cats before, mostly with a Rage 2 blade though. :thumb
 

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is there any codes that can be throw with gutting the cat.
 

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Let us know what change you see in your fuel economy, if you would, please.
 

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why not buy a delet pipe and just remove the cat . so if you ever need it againe you have it they are really resonable 100-150 and the delet pipe doesn't have any bends which will flow better
 

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is there any codes that can be throw with gutting the cat.
I have never had any codes in 20,000 miles, much of it towing. I don't notice any real MPG difference, but EGTs are lower by about 100*.
 

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Discussion Starter #18
Guys, the truck sounds awesome. Like a fricking jet plane when you get on it. When just cruising around, the exhaust is not loud or obnoxious. At idle, the truck sounds like a big block Chevy. When slowing down to a stop, you can hear the turbo whistle. Driving on the freeway on flat stretches, my EGT's are at or just below 500 degrees. Very happy with the results. I will be going back to my local dyno shop and see what it will do. The hp and torque in my signature was with the non-Race PPE Hot+2, which was through the CAT and DPF. Now my wife on the other hand, makes fun of the stack exhaust and the whole "diesel thing." I've threatened to put a stack on her Mercedes :D
 

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Just picked up an extra Kitty today....Going to do this mod on my spare Kitty this weekend.
 
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