My DPF looks like it is ready to fall off. I have the 409 stainless DPF back MBRP now. I drive this truck in the mountains during the winter and we use a de-icer in this state. After a little of a year my 409 stainless has a lot of "scaling" rust on it. Since my truck is lifted the rusted pipe shows more. Does the 304 or new black stand up better than the 409 stainless? Should I get the new pipe coated like a ceramic or something?

Yes, the T304 pipe will slightly discolor, but should stand up much better than your 409.

I bet that black would show all the salt/de-icer pretty bad?

I would suggest the T409 if you plan to keep the truck more than 5 years. If I can help let me know.

The T304 is not going to rust like the T409 will and is definitely what you want if the whole system is visible. The problem is, MBRP doesnt make a full kit in T304. You would have to get a T304 cat back kit and the T409 front pipe separately. Silverline makes a full T304 kit though. If youd like a quote on anything, let me know.

also mbrp doesnt warranty the black in harsh conditions. not sure what there guidlines are for harsh conditons

I would suggest the T409 if you plan to keep the truck more than 5 years. If I can help let me know.

The 409 scaled pretty bad. I don't think I would go that direction again.

It won't rust through though. It will eventually look like crap on the surface however.

That's what I am trying to avoid. Especially since it can be seen with the truck lifted.