well, I really want to take the cat off this thing but I don't want codes, at least until there is a programer that can erase the darn things. Anybody figured out a way to fool the egr? Mcrat did ya take that muffler and kitty cat off this weekend?

No EGR codes after >300 miles. I'd say the water's fine.


Stock muffler is still on, I'm going to try an experiment to relieve backpressure, a Monster Cutout... Was supposed to do it Saturday, but I was short a flange. I'll post pics and dyno results when I get it done.

That is not really a cat as on a gasser. It is not monitotred by a O2 sensor. You can take it off without a problem.


They are only really effective with the low-sulfur diesel overseas that we do not have yet.

well the problem is, I beleive anyway is that the back pressure it creates helps to operate the egr valve. I have my muffler off but cat in place. I think, from what I can gather, you need one or the other to give the necessary back pressure to operate some sort of valve in the egr apparatus to avoid codes?

Dmaxallitech, can you help us here?

I have had my full dynomax kit on for about 500 miles, i just took it off to get it coated, and I never got any codes with it on. What a difference with that cat gone.

Some are getting codes and some are not...http://www.dieselplace.com/forum/smileys/Ermm.gif


I don't think anyone's tried to pin this down to different exhaust manufacturers, or if it's an individual truck thing, but some are getting the insufficient EGR flow codes set with the CAT removed.

No codes here, >400 miles

No codes here with 5100 miles !!! I have 4" turbo flange back with no cat and magnaflow muffler ! Luv it !http://www.dieselplace.com/forum/smileys/Approve.gif

had mine off for about 3000 miles now. no problems at all

had mine off for about 3000 miles now. no problems at all same as me