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Is there a 4 or 5" exhuast kit for a LBZ that includes a catalytic converter? I would like to have an oversized exhaust and keep it legal at the same time.
 

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I haven't seen one yet. I think the only way you can keep your cat is to just do a cat-back system. I'm glad mine never came with a cat, so I wouldn't have to worry about that.
 

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MBRP cat back 4" Available in single or dual exit. Just installed one on a brand new LBZ. Clean looking, not very loud at all. Same kit, add the cat delete pipe and you have a downpipe back kit.
 

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you could get a after market cat and a system from a company i cant remember there name ill see if I can find them.
 

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you must live in a state that visually inspects yearly or what?
 

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If there was anything you could possibly do to get rid of the cat I would do it in a heartbeat. Very restrictive and they keep a lot of heat from getting out away from the turbo.
 

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That seems to be one of the worries about the new diesels coming out designed to run on the ulsd. Apparently emissions are so strict that there are all sorts of filters and scrubbers in the exhaust to try to keep the crap from getting to the environment....
 

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sounds good

I have my 06 with 4" straight pipe. not extremely loud until full throttle, then sounds like a jet.. runs and sounds good though.
 

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I have my 06 with 4" straight pipe. not extremely loud until full throttle, then sounds like a jet.. runs and sounds good though.
Do you still have your cat on? if not are you getting any check engine lights yet?

Thanx
Caleb
 

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no cat.. i got a code once for insufficient egr flow. when i plugged into it the checkengine light went away. im sure it will come back again. i was pulling a fairly decent hill when the light came on. once in about 5000 miles now.
 

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There is a little device you can buy to keep the code from setting called a finger stick, there are only two places you can get them, from the guy who makes them (Fingers) and from kennedydiesel.com im prety sure they are like $20 na dthey are not hard to install and after you instll that you can put a blocker plate in the egr also! if you blocked the egr with out a finger stick the light would come on all the time because it would not be getting anyflow at all!
 

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Are there any significant gains by taking the cat out?? Or straight exhaust versus a muffler? What about blocking the EGR? Any gains?

Mine has a straight pipe in place of the muffler now, but still has a cat. Any input would be awesome!

Thanks!
 

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I believe that the muffler is more restrictive than the cat, but you can't really hurt by taking it out. The gains won't be significant, or noticeable powerwise but it should help give you even more EGT reduction.
 

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That's what I figured. Is removing the cat and muffler good enough to run a programmer without getting the EGT's too high?

I've heard both ways, just lookin for some more input before I buy an exhaust system.
 

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EGT's might get "high" depending on what programmer you go with. But "high" EGT is all to often viewed as excessive by some, when in reality high EGT's in short bursts will not do any damage to anything on your stock truck. The exhaust mods will help keep it cool.
 

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That's what I thought....I build race cars, not diesel trucks!! Just though I'd make sure before I got too ahead of myself with the programmer.
 

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If you get out of a comfort zone on your egt provided you have a gauge to view it you can either use a lower setting or you can throw on a small shot of nitrous. Or you could get a snow performance water/meth boost cooler...
 

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Yeah, I know....I'm actually considoring propane...For fuel milage reasons. I haven't studied up on the water/methanol enough yet so I dunno.
 

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Propane from what I have heard and read isn't really the best choice. You can get better mpg's with mods such as intake, exhaust, and a chip that isn't set on it's highest level but just "economy" mode if it has such an option. That along with light footed driving practices make for great mileage.....and leave your tailgate up too! You'll have to think whether the investment in the entire propane system with the tank (which can be expensive) and the cost of the propane fillups if you will actually gain much if anything in the long run. If you only get 1mpg more with it how long will it take to "pay" for the benefit? As far as power it supposedly works well, but again it's not the top choice with many.
 

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N2O has been proven very dangerous to the dmax, almost all of the dmax engines i'v seen with holes in them was from to many drugs, Water/meth and propane are alright in extreem moderation but have still caused blown engines! The duramax is a very different animal, you can get great miliage and power and driveability all with just tuning and other minor mods. unless your looking for that last hp and can risk popping an engine i would stay away from the drugs!

JMO
Caleb
 
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