mr. ed

I've read on some of these threads that the tailpipe on a stock 6.7 should remain clean with no trace of soot due to the cleaning action of the DPF. The inside of the tailpipe on my truck (36,300 miles) is black with a thin coating of carbon. The truck runs very well and I notice no trace of smoke while driving. So, is it normal to have a little soot in the pipe or should it remain squeaky clean with the chrome showing? Is the carbon coating indicative of a failed DPF? Thanks for your input...

mega-engr

Interesting. My tailpipe is clean as a whistle, for now...

It should be very clean, does not sound "normal" to me for a properly operating system. No codes or CELS?

sabersix

When I sold my 2007.5 with 24,000 miles, it had the same light black coating and would get some light soot on the bumper. I mentioned the soot to the service dept on one visit. They flashed the ECM and sent me on my way.

I suspected a cracked DPF, but never had a CEL so could not really do anything about it. Probably a small crack or hole allowing some soot through but not enough to throw off the emissions sensors.

sabersix

Oh, my new 09 is still clean at 3000 miles.

donaldej

There should be NO soot in you tail pipe. When mine did that it was a cracked DPF which they fixed under warranty. The big brown truck is going to pull in my driveway July 6th which will cause my DPF to fall off.

Dale_K

Mine is perfectly clean at 24k. I don't think you should see any soot on a stock truck that's working right.

mr. ed

Well that's very interesting, guys. No, the truck is throwing no codes and is running perfectly well. Here's my plan:

Supposing the DPF is defective to some extent, what if I just keep running the truck as is until I reach higher mileage, let's say around 70-80k? Then I would have a new DPF installed while still under warranty. Whaddya think?

mega-engr

Why not just get it fixed now under warantee and then it can fall-off and easily be put back on when needed?

mr. ed

I hear what your saying, Mega and as much as I'd like to delete this stuff I want to remain stock for now. I'm concerned about the legal issues that could arise if I were caught since I travel frequently through different states. Besides, I'm not mechanically inclined enough to do the deletes and then have to put everything back together if/when the situation warrants. About the only thing I may try is unplugging the EGR but other than that I'll take a "wait & see" attitude. I may change my mind later as I learn how others are doing with their deletes and if anyone runs into legal issues over it. Thanks....

JP-4.5

mr. ed... sounds like a good plan to me...
Maybe being cracked will help your mileage by allowing a little more flow than stock?

tnhtractors

83500.0 miles on my 08 and my tail pipe is clean with no trace of black soot. its the most amazing truck I ever owned.

mega-engr

I think I saw a thread a while back that sounded like someone was "cracking" the DPF or something on purpose for similar purposes. Like drilling a small hole or something through the core.

Interesting that there are no CEL issues and shows some soot. Maybe there is something to a cracked or modified DPF.

However, this is just another bandaide to avoid a CEL issue and there are many more improvements that are legal to the system such as updated flash and TSB...

mr. ed

You know, I was thinking the same thing. Maybe it's good to leave it on as long as practical OR maybe get a new one installed under warranty and keep the old one to reinstall sometime in the future when the new DPF gives up. The old DPF would act as a "facade" since no one would be the wiser if a visual inspection by some authority couldn't discover anything wrong.