Hey Guys...

I hear everyone talking about 4" and 5" exhaust systems on this site... Has anyone used their stock exhaust and just deleted the muffler and Cat yet??????

I seem to continue to get mixed reviews on removing the Cat and the PCM setting codes...

Ive heard it's only significant on 03's and 04's...

Who has the CLEAR answer... Will it set codes on my 06 LBZ???
I REALLY dont wanna hack my wiring up to install a Finger Stick!!!

Does ANYONE make a free flow converter for the LBZ???

HELP!!!

Thanks Again Guys!

My buddy runs the stock system with no muffler or cat. This is a federal emissions truck and yes he did throw a code when he removed the cat. This is on a 2006 GMC LBZ. On my truck w/ a 4" straight pipe I have NO codes, becuase I installed the blocker plate/fingerstick prior to the exhaust. There are bigger diameter high flow cat's available but they are pricy. Not sure who makes them either.

Jason

Magnaflow makes some high flow cat's.

http://www.car-sound.com/02product/universal/600d.asp

If you get rid of the muffler and cat, you will most likely throw codes. If you dont want codes, just do the muffler.

I have the cat deleted on my 06. Muffler going to go soon. I didn't throw codes, but like Rebelchevy, I too installed BP & FS prior to exhaust mods. This is only a temp. set up for me as stacks are coming at the end of summer.

How about if I get rid of the muffler and install a free flow cat?

Where the MOST restriction... Cat of Muffler????????

I have no data to back this up, but the cat seems to be pretty open, and I read somewhere on here that the stock muffler gets pretty small inside. I know when I took the muffler off though, there was very little sound difference until I removed the cat as well.

Here's my buddy's 06 LLY. It is loud when he gets on it. Stock pipes, muffler and cat deleted, no codes. PPE is only current performance mod.

On my 05 LLY, cutting out the converter made the biggest difference in my opinion. I have not gotten a code in almost a year of driving now. Some trucks will light up as soon as you start them back up with no cat though. If you're looking for sound, ditch the cat.

http://www.youtube.com/watch?v=taAYZZ4XZEo

http://www.youtube.com/watch?v=bWFwIYslAlU

Smoker...

How'd u guys do the pipe between the muffler... Bet it was a cheap fix... cheaper than 500 to 700 in a kit that's only 1/2 inch bigger.

You could also look into a programmer that basically does the samething as a fingerstick. EFIlive and the PPE programmer will eliminate the codes, maybe some others will too.

Smoker...

How'd u guys do the pipe between the muffler... Bet it was a cheap fix... cheaper than 500 to 700 in a kit that's only 1/2 inch bigger.

All we did was weld in a small section of 3.5" straight pipe where the cat was. The remainder of the pipe was let untouched. His also has a sleeve where the muffler was.

After hearing his and not wanting that much noise, I went with an MBRP muffler off ebay ($50) and then also scored a 4 inch tailpipe section off ebay as well so I'm running a sleeve where the cat was and an MBRP muffler and tailpipe.

Rebelchevy87:

I had the idea of putting on a high-flow cat so I wouldn't need to block & fingerstick the EGR. Unfortunately, the Magnaflow tech told me that their high-flow diesel cats would still throw a code. :(

BoiseRob

On my 05 LLY, I found a used 4" cat MBRP cat delete pipe for $50 bucks and just put a piece of flex pipe in place of the muffler. The flex pipe worked for about a year is all and rusted out, so my local exhaust shop ordered a direct muffler replacement from MBRP. I think I paid $60 for that. Installed everything myself so all in all, I got by fairly cheap. Also, no codes or SES light since the mod.

I Eliminating the cat is going to give you the most change in sound. I first removed muffler only and there was hardly any difference at all in sound.

:banghead: This is horse ****...
These dealers dont wanna be straight about ANYTHING! I have called several in my area and all I get is well if you have a problem and the exhaust is altered you're SOL! If it directly relates to the problem with the motor...

Looks like I'll have to get out the farm-boy handbook and engineer somethin'!!! I believe I can make something with a flange similar to the aftermarket units so I can remove it if needed. Damn the aftermarket Cats are almost $400 bucks...

Thanks Guys...

:banghead: This is horse ****...
These dealers dont wanna be straight about ANYTHING! I have called several in my area and all I get is well if you have a problem and the exhaust is altered you're SOL! If it directly relates to the problem with the motor...

Looks like I'll have to get out the farm-boy handbook and engineer somethin'!!! I believe I can make something with a flange similar to the aftermarket units so I can remove it if needed. Damn the aftermarket Cats are almost $400 bucks...

Thanks Guys...

Cut the cat out and gut the thing then weld it back in.

:exactly: Cut the cat out and gut the thing then weld it back in.
wanna talk about some farm engineering, this is the way to do it,this is how we fixed our 6.2 on the farm back in '85

AAHHHH....Yes... The good OLE days!

I have an 05 LLY with no cat or muffler. I'm running an LB7 front pipe and used some 3.5" elbows and a straight section of pipe to delete the muffler. No light, however I do have EGR codes, just not enough to trip the light. I also have a blocker plate with an LBZ intake. Just my .02

i have a 4'' turbo back no cat or muffler on my 06 lbz and im in ca...no codes..and i dont have a fingerstick. i have an egr blocker plate but i havent put it in yet. Pinnacle exhaust from T & J diesel performance... they are a vendor on here and for the price you cant beat it... fits and works great... about 270 shipped. PM me with any questions or if you want pics or sound clip

i have a 4'' turbo back no cat or muffler on my 06 lbz and im in ca...no codes..and i dont have a fingerstick. i have an egr blocker plate but i havent put it in yet. Pinnacle exhaust from T & J diesel performance... they are a vendor on here and for the price you cant beat it... fits and works great... about 270 shipped. PM me with any questions or if you want pics or sound clip

I have the same exhaust on my LBZ, sounds awesome, I had the BP/FS in before the exhaust though.

i dont have the fingers tick but i do have the egr blocker...no codes....but i havent been able to get egr blocker in... i cant get those bolts loose...help please:(

Twister...

Yeah... I'd love to see some pics and sound...

Do share!

Thanks

I have a 06 lbz 4" cool duels no cat or muffler no codes at all acutally before i bought if you look where the front pipe conects to the down pipe i unbolted that to se how it sounded and it did not throw any codes sounded something like a jet but if you get codes bully dog chip and also the outlook monitor with fix that

i pulled the cat down cut the top off and pounded the $h*t outta it till she was empty welded the top back on (3"x3" square) then bolted it back up done and sounds great and your dealer wont notice it if you do it on the top mine hasnt in 3 trips there

i dont have the fingers tick but i do have the egr blocker...no codes....but i havent been able to get egr blocker in... i cant get those bolts loose...help please:(

PB Blaster and A 3/8" Flex Head Long Handle Ratchet w/ a deep socket Should Do the trick. Try it when the motor is still slightly warm.