Working on customers '06 LBZ dually. We did Edge programmer and 4" exhaust, getting rid of the cat. conv. It popped a CEL /w an EGR code for insufficient flow. We're fairly new to D-max's and not sure how to resolve this. Does it need PCM reprogrammed, or is there an easy mod? It worked fine for a few weeks until he hooked up his trailer, then popped it on under load.

Thanks for all your help.

John

OK, so I should have searched a little more first. Looks like a finger stick and blocker plate will fix the problem. Thanks for the help :D hahaha

John

Exactly!

Since you are working on the very thing I want to do with my truck I thought that you could answer me a question....My buddy, a mechanic, doesn't believe that I will get better fuel economy if I go with a 4" exhaust and remove the cat. conv. I don't feel like I can argue with him as I don't know the dynamics behind the diesel engine and why it would give me better fuel economy if I did it. All I know is that I want to get it done because everyone I talk to said that it would improve my fuel economy. SO, my question is... does removing the cat. conv. and installing a 4" exhaust from the turbo back improve fuel economy? ...and if so why?

It will definately help. The stock exhaust is VERY restrictive with the cat, factory muffler, and 3.5" tubing. Removing the cat, going with a high flow muffler, and 4" piping will greatly reduce backpressure and help the engine "breathe" much easier. This improves the overall efficiency of the engine which results in better power and mileage.

all motors wheather gas or diesel are nothintg but big air pumps, and the easer you can get the air in and out of the motor, the more efficent, which equals more power.

so it takes alot of HP for your motor to SUCK in air, thats why turbos really help, the turbo forces air into the motor, and the HP your saving is now at your disposal

Rick

I know with the gas LS series motors, we can just have a reputable tuner turn off the EGR monitoring system altogether; can we not do this on the Duramax? I have EGR block-off plates on my LS1, and have had my friend and tuner Corey Henderson disable the EGR system and knock retard sensors. I'm new to the diesel side of the house, so forgive me if this has been asked before. Personally, I would rather disable the EGR system at the source.