Landon Matthews

Howdy Folks got a couple questions about California smoke test. Took my truck to get it to pass smog 2001 Cummins, both smog shop said that truck blows too much smoke and wouldn't even test it. No tuner stock injectors need help!

Danderson

Boost leak,worn injectors to start.
Are you in San Diego or close by? There's an honest shop here I use.

Midnite

Yep, most likely boost leaks, or even an old clogged up air filter.

The stock rubber intake boots (sometimes also called "hump hose") very commonly get small pinhole leaks. A good shop can easily pressurize your intake system with shop air and find the leaks with soapy water. On a truck as old as a 2001, it's pretty much guaranteed that you're going to have small leaks on multiple boots.

73CrewCab

These are the cheapest silicone boots I’ve found. I’ve run them on my 12 Valve for about 5k miles, and had them off and on a few times (for other modifications to the truck). They’re holding up great. I spray a light film of WD-40 in the boots and they slip right on. And I haven’t had any clamps break or come loose. I paid about $20 more ordering them through amazon, because I didn’t know you could buy direct.

1994-2002 Dodge Cummins Silicone Interooler Boot kit, Diesel Speed Shop

Danderson

Another source.
https://www.dieselpowerproducts.com/...CABEgL_8PD_BwE

AlpineRAM

If it's a snap test the main reasons for smoke are:
Clogged air filter
MAP and IAT sensors reading wrong.

This is because at the snap test the turbo does not have time to spool up, so leakages in the turbo and intercooler piping are not really relevant.
(Nevertheless fix all leaks there, power, egt and fuel economy are affected by holes there)

I'd start by replacing the air filter and cleaning the MAP and IAT sensors.