Noticed that there are quite a few of you out there that have straight open pipes from the turbo back. Will this effect emissions at all? I live in AZ and they perform a smog every year. I don't want the hassle of failing smog test for the sake of open pipes.

Install a high flow soot trap for the exhaust. It only reduces particle emmissions minutely for a few years then gets clogged.

The way I see it, Getting a good burn on your fuel is the long term solution. When you have the intake and exhaust opened the engine breathes easier and EGT's are reduced and soot formation as well in an efficient burn (that would be when your stomping the pedal and you don't see a black plume behind you.

I have my GM-4 turbo sprung shut and I see the tiniest puff of black when I floor it from a dead stop and no trace of exhaust afterwards. I could pass your states snap test because my engines running at peak thermal input from the turbo and my timing is 5 degs advanced, plus the optical bump.(not to mention I'd add a hot fuel mix before hand, can you say ethyl vegtable fuel oil emulsion). The hotter the combustion the less soot formation.

In park when you mash the pedal on mine (like the snap) the turbo holds it's pressure for several seconds and it doesn't return to baseline idle 'till the pressure stabilizes, usually heard as the whistle. The vac system is designed to gut your boost pressure at all times, the more input the more it reduces it.

Sorry QM, you'll have to excuse my lack of experience or knowledge about diesels, so don't get too crazy on me.

If I were to order, say...the Banks Stinger system or a different system from a different manufacture, how is this going to effect my emissions? As far as the soot trap, this is what I see between the turbo and the muffler....right (on gassers this would be the cat)? So what your saying above, the traps only last a couple of years?

Yup, they clog up real fast. If you ask me, they do more harm than good overall, but I am not an emisions expert by any means. A good cat back system will not hurt your emisions at all. If anything because they help to make the engine more efficient, your emisions should get a bit better. Just make sure that before you go in for the test to:

- have a good clean hi flow air filter
- new fuel filter
- recent oil change
- a good quality additive in your fuel
- And make sure the engine is completely up to opperating temp before you go in and you should be fine.

Good Luck!:)

I've never had a problem passing emissions with over 100K miles in it. I just don't want to start modifing the old man, then the state slaps a repair ticket on it for failed emissions. I know how much of a pain it can be to track down an emissions problem. From what I have gathered, completely eliminating the soot trap should not effect it that much. What if this was the only mod I did (exhaust), whould I eventually have problems now and/or in the future? I don't mind replacing the soot trap, I just want to get the facts before it's too late.

The soot trap doesn't do that much but it is visually reassuring to an inspection officer. I think starting with the downpipe on some years can be the best move.

I put a new turbo back exhaust on my '95 Burb, and now I can't pass emissions. Removing the Cat is a risky proposition if you live in a State that requires emission tests for diesels.

They don't do emission tests on diesels here in VA, but who knows when they will, as the gasoline burners get very strict testing currently with a dyno.Censored EPA.

I want to run 3-inch exhaust all the way back from my 3-inch flowmaster downpipe as I bet my soot trap is providing a large restriction. I plan to rtain the shell of the trap so it appears functional, just in case.

Sounds good guys. So if I wanted to install a new down pipe and a catback system, what are some of the recommended systems/manufactures out there that will give me the best performance for the buck? Also places to look for a soot trap would help as well.

you guys that have e-check, ask em what they are testing for. either hydrocarbons or nitrous-oxide or both?

Nevada checks for visual (SES light, EGR, if installed) and soot trap. They also check the opacity of the exhaust while on dyno. However, the tech told me that the limit is so high that if the engine is even running it will pass.

not sure if u could get by with it but jc whitney offers a exhaust cutout, straight pipe when u want it

I just been told that I can use a regular muffler from a gas engine on my diesel, is this true? If so, my possibilities are endless......