DOC???? Does it really help?

[CDUBYA]

Ok, i have read all about the DPF delete and we all know what gains we see from it and that is awesome when its gone. Mine is!!! Anyway as far as the DOC/CAT goes. is there really any true gains or differences in performance sound etc when taken off and acutally done a complete straight pipe????

Reason i ask is because my buddy has Job 1 truck one of the first new 08's made and he now has 90xxx miles on it. never had one problem with btw... but after taking to the deisel shop we all go to around here, they are very good btw, they say they ran test after test on his truck on whether the CAT made a difference on or off. their conclusion was that it made no difference what so ever other then the fact it is illegal to take off and for some reason HP around here cares not one little bit about the DPF off but when they see a CAT off they write you up for a big one.

Anyway some of you who have complete straight setups: Have you seen any dofference in it at all or what are all your opinions on this. this thread will determine whether i take mine off or not. i currently run no DPF with edge programmer and S&B intake. wondering if i would see anyhting at all with no DOC/CAT???

Thanks

[HoosierHick]

I still have my cat with my spartan tuner and DPF delete and I think it runs pretty strong. I am planning on cutting it out so I'll let you know what I find out.

[CDUBYA]

sweet, yeah let me know how that goes! thanks

[amb82]

I am pretty sure the only problem with leaving the DOC on is it eventually will plug from all the soot. I run the spartan 250 tune and judging by all the black smoke that comes out when you stomp the pedal I would say over time the DOC would get coated up and clog

[Big Angry Hillbilly]

It will deaden some of the sound as well.

Personally, I think a DPF/DOC delete pipe would attract much less attention -- if you could color match the pipe to the rest of the exhaust.

A DPF-Only delete pipe screams "HEY! SOMETHING ELSE GOES ON AFTER THIS CAN LOOKIN' BUSINESS HERE!".

Especially if you have any sort of lift, it makes it plain as day.

[CDUBYA]

ok, that makes sense. But does it actually clog up? Does anyone have any experience with this, and as far as power and mileage goes does it do anything to increase either?

[08spartan250]

i have the 5" straight pipe and i absolutely love it. its going to give you a lot more flow than just the DPF delete pipe. the full exhaust will give you some added horsepower. and for the sound, it is AMAZING. i can't count how many people have told me that my truck sounds like a jet when its at idle. and when you really get on it, it just screams. i can hear it echo off of towers 30 yards away when i go past them. i would highly recommend going straight piped!!

[powerstroke43]

i have a hollowed out dpf with the doc. Spartan tuned for 15000+ miles. It hasen't cloged and I don't see how it could be any different than a stock truck since the doc is before the dpf. I don't think I have any less power or mileage by keeping it.

[fordfish]

Originally Posted by powerstroke43

i have a hollowed out dpf with the doc. Spartan tuned for 15000+ miles. It hasen't cloged and I don't see how it could be any different than a stock truck since the doc is before the dpf. I don't think I have any less power or mileage by keeping it.

Wow that's ballzy, what are you going to do if you develope some problem and need to get it to the dealer for a TSB, do you have any extra setup? Or does your dealer care.

[powerstroke43]

Originally Posted by fordfish

Wow that's ballzy, what are you going to do if you develope some problem and need to get it to the dealer for a TSB, do you have any extra setup? Or does your dealer care.

I got an extra dpf. I still have the one that came on the truck. My dealer said he didn't care but I still wouldn't risk taking it without putting the real one on. My dpf looks stock, but anyone that has half a brain could figure it out.