Newbie needs exhaust help

[cchicoin]

So I've searched but can't find any definite answers. I just bought an 02 7.3 and it has a 4" straight pipe. My main objective is to plow with the truck but it's way to loud. Problem one, the truck has no cat and the inspection station believes it may have had one from the factory and would like to see one reinstalled. Problem two, the exhaust that is on it is way too loud for plowing residential areas late at night, it's fine for me in the cab but I feel sorry for my customers. Is there an aftermarket turbo back or cat back that's less restrictive than stock but is as quiet? I'm probably trying to have my cake and eat it too but you guys would probably know more than I would.

thanks for your help

chris

[Raul@Stealth Automotive]

first off welcome to the Org Chris....

second have them prove that your truck came with a cat from the factory.... i believe they can run your VIN and find out....

you might want to put a muffler on it.. it will deff help quite it down a bit....

their are no aftermarket exhaust that will dampen the sound... the muffler is the key

-Raul

[dleopard19]

where im from diesels dont go through emmisions but get a mbrp muff, everyone i talk to likes the straightness

[snakyjake]

I read good reviews about the Walker Big Truck Muffler.

[Tim Langley 1997 f-350]

yeah you shouldnt have to have a cat on any diesel older than an 07 it did come with one but it is not required equip leave the 4" and just put a muffler on it

[TurboSevenThree]

Originally Posted by Tim Langley 1997 f-350

yeah you shouldnt have to have a cat on any diesel older than an 07 it did come with one but it is not required equip leave the 4" and just put a muffler on it

Correction, he shouldn't have a powerstroke diesel with a CAT any older than 2003.5-ish. I believe the last 7.3's had one, and all the 6.0's had one AND an EGR. Anybody wanna tell me I'm wrong just to be sure?

[Tim Langley 1997 f-350]

what i meant was he legaly doesnt have to have a cat on a diesel older than an 07 and my 1997 psd had a cat on it factory

[NCHornet]

Originally Posted by Tim Langley 1997 f-350

what i meant was he legaly doesnt have to have a cat on a diesel older than an 07 and my 1997 psd had a cat on it factory

Totally FALSE!!! You may be able to get away with it now, but it is still illegal to remove any emissions equipment that came on the truck from the factory. I don't know where the OP lives as I wasn't aware any states are requiring emission testing yet on diesels, but I promise you it's coming and states like CA. will lead the way!! My local guy says by 2010-2012 emissions on diesels will be required on diesels in NC. The first part of the test is a visual inspection, no cat, or muffler on a truck that came from the factory with one is a automatic fail!! Some PSD's had them some didn't, running the VIN should tell you.

Back to the OP. Here is the problem, the most quite muffler will be a offset design, but this causes restriction and raises EGT's which you don't want. A straight shot muffler like the Walker BTM from Napa ( $45) won't raise your EGT's and are not that much louder than stock. I know the BTM is available in 3.5 and 4" . As long as you have a muffler I can't see how they can say anything but I am curious what state this is in and if these restrictions affect you because you are commercial?
NCH

[Tim Langley 1997 f-350]

ok well as of the 2007 model year on all diesels nation wide they are required by federal emmisions laws to be equped with particulate filters and smog equipment and by 2009 all diesels model years 2007 and newer will have to go through i&m smog or deq smog

[cchicoin]

So I just called a California dealership and they only asked what year it was. The tech said that 02 didn't come with a cat and they only look for a muffler to pass inspection. If it'll pass in cali without a cat, it should pass here. I really appreciate your information though, this is a great forum!