Okay everyone I have a question. But first let me tell you what I have. I have a 09 chevy dmax extended cab short bed. I currently have a 5 in turbo back mbrp straight pipe exhaust. Well I'm up for an inspection and no one will inspect it because I dont have a cat or muffler. So this is what I'm doing. I'm using the stock part of the exhaust with the cat and got a 5in mbrp cat back exhaust with a muffler. I had someone install my straight pipe and they messed it up. I cant even hang my spare tire so I'm taking it to someone else this time.

Now to my question. The directions say I have to cut 9 1/2 inches off the longest straight section of pipe on the mid pipe. Which peice is that, is it number 3? The piece that goes up and over the cross member? It also says that I dont have to use the 18in extension pipe at all. Is that number 4?

So which end and which piece is the mid pipe? and is number 4 the 18in extention?

If you couldnt already tell I'm not mechanically inclined. Now if it has two wheels I'm good to go.

Thanks-chris

The link is a picture of the instructions so you know what mean when I say number 4

Why not just bolt your stock stuff back in for the insp? That's all I am going to do! 45 minutes is all. Plus time to re-program the ECM back to stock.

for me with my job I just cant do that. Its easier for me to do this and be done with it all together.

pa32rt, Am I understanding the directions properly?
thanks-chris

Can anyone please tell me if I'm understanding this correctly?

About the cutting and such with the DOC, I don't know.

But, again, I don't see why you would through ANY labor other than to install the stock system back. If you are worried about the inspection - they are gonna fail you on the missing DPF anyway, right? So the DOC is a moot point.

My dealer said all I need it a cat and a muffler. What is the DOC?

My dealer said all I need it a cat and a muffler. What is the DOC?
It's the official name of the "cat". Cars have catalytic converters. Diesels have Diesel Oxygenating Cannisters.

Your truck came original with a DOC, DPF, and muffler - in that order. I can't imagine why the dealer would tell you only to have a DOC. The muffler doesn't matter, as far as emissions, so I would imagine he said you need a DOC and a FILTER? Unless he thought you had an old body style truck? The DPF is also known as a soot filter.

Ok I didnt know that about the diesel oxygenating cannister. But is exact words were that I need a "visual on the cat and muffler". I'm not cutting the DOC. I need to cut 9 1/2 inches off one of the pieces of pipe in the new exhaust kit and my question was which piece is it?
Thank you for your help. I too find it odd that I dont need the DPF on the truck. But here in PA there is no emissions rules on diesel trucks. The reason for the DOC and muffler from what they told me is for "safety" reasons.

But here in PA there is no emissions rules on diesel trucks. The reason for the DOC and muffler from what they told me is for "safety" reasons.
Makes absolutely no sense to me, but I don't live in PA, either. If there is no emissions testing for it, then it doesn't need a DOC - in reality. I don't see how a DOC is a safety piece, since it would be the hottest thing under the truck. It heats up and helps to "burn" some of the soot. This is also why it is in-line BEFORE the DPF - it gets the exh temp HOTTER prior to entering the DPF so the DPF only has to heat up a bit more for regen cycle.

Other than that, it really does NOTHING - other than restrict the exhaust.

Chris:

I did a quick google search on the mbrp product you purchased. these instructions seem a little better and clearly indicate the "mid-pipe"

http://www.mbrp.com/products/instructions/S6022.pdf

good luck.

Moved to Fuel System, Air, Exhaust, & Emissions Upgrades...

wow those instuctions are much better! Thank you very much. I'm glad I didnt screw up the new system