I'm planning on doing my exhuast next week, and have to make a decision soon. Do I run a straight pipe off the cat and exit. Or put a performance muffler in also. I want some good sound, but I also have to keep it at a decent db level. I use the truck for work so I have to keep it decent. So has anyone done just a straight pipe?

I was thinking that the cat is not something that can/should have a ton of diesel exhaust though it and still work for a smog check??? The gassers don't last real long and a diesel is going to put a lot more oily, smokie junk though it. So, I was thinking the cat would be a lot more comfy in the shed waiting for the day if/when I have to smog this thing here in the wounderful world of Socialist Republic of Kalifornia. I am going 5" with the 4" down tube. I may use a Resonator (goes where the cat is) and the after market muffler if it is tooooo loud or gets a drone on the freeway.

http://www.xtremediesel.com/browseproducts/MBRP-Diesel-Resonators-(Aluminized---Stainless-Steel).html

http://www.rpmoutlet.com/duraexfive.htm
The EGR blocker is a big deal to me and I need to order it.....

I have did a 5 inch cat back MBRP exhaust. I have to say i am pleased with it. I now have a noticable deep tone but its not to load. I have heard of alot of CEL with cat removal so you may want to think about that although they are suppose to be coming out with a cure for that if its not already out.

I'm planning on doing my exhuast next week, and have to make a decision soon. Do I run a straight pipe off the cat and exit. Or put a performance muffler in also. I want some good sound, but I also have to keep it at a decent db level. I use the truck for work so I have to keep it decent. So has anyone done just a straight pipe?

You will have to put the cat back on if you need to take it to the
dealer for warranty service plus you will be getting a code from
the computer.

Has anyone done a test to see how much the cat restricts flow? I've read posts where guys have done cat back systems and no CEL but, as soon as someone removes their cat (either with stock or aftermarket system) they get a CEL for insufficient egr flow which means the truck is sensing less exhaust back pressure. The truck doesn't seem to notice any difference from the cat back but as soon as the cat is removed, bingo! less back pressure. So it would seem the cat is the most restrictive part of the exhaust and a cat back exhaust doesn't really do you any good.

Uh...the cat restricts alot!!! I can tell you first hand. I just did my exhaust today. No muffler, no cat, no cel! Holy....lot more power!!! Very happy!!!

Has anyone done a test to see how much the cat restricts flow? I've read posts where guys have done cat back systems and no CEL but, as soon as someone removes their cat (either with stock or aftermarket system) they get a CEL for insufficient egr flow which means the truck is sensing less exhaust back pressure. The truck doesn't seem to notice any difference from the cat back but as soon as the cat is removed, bingo! less back pressure. So it would seem the cat is the most restrictive part of the exhaust and a cat back exhaust doesn't really do you any good.

What kind of exhaust systems are you guys running?

I'm running the TMW 4" mandrel, aluminized. Its a very nice kit, its a guy that I do machine work for out here in AZ that makes them. I can sell the 4" kits for $350, and the 5" is $100 more. No tip included, but it comes with everything including the muffler delete and the front pipe, and clamps, with hangers. If anyone is interested I stock both kits, all this is plus shipping of course.

What kind of exhaust systems are you guys running?

I pulled the muffler, and put a mandrel bent, muffler replacement pipe in its place, and the only things I noticed was slightly quicker spool, and more whistle. The exhaust not did not change very much if at all. :)

moving to exhaust

Take the cat out and hold on

I pulled the muffler, and put a mandrel bent, muffler replacement pipe in its place, and the only things I noticed was slightly quicker spool, and more whistle. The exhaust not did not change very much if at all. :)

Thats definatley next on the to-do list. I just want to wait till my fingerstick gets here...