After reading the post yesterday about how to correctly set the tire size.........I went back and reprogrammed my Predator and changed the tire size correctly !!

While I was at it I cut the EGR back on !! Why ???............well on my Hypertech I was getting about 4 mpg better on average ........with the same driving style !! So I was just going to try this and see if my milage improved !!

OK........the crazy part..............since I recalibrated the tires and switched the EGR back on yesterday................the truck seems to be running better ! It feels a tad smoother , shifts a tad smoother, but mostly feels more responsive !! I may just be crazy..............I don't know(first deisel)........there is probably no logical explanation for this........but it sure seems to feel better !!

What do you guys think ??? I just have a cat-back exhaust and I was getting codes before.........no light........so I had the EGR off to not get codes !! Could it run better with the EGR on and getting codes ?????????

IF I am correct......Turning the EGR on/off with the predator does not actually turn the EGR valve on/off. All it does is allow EGR diagnostics. In other words....If you have the egr valve unplugged or blocked.....with egr diagnostics ON you will get codes and maybe even CEL, but with egr diagnostics OFF....you shouldn't get either.

It could be a totally valid feeling, or the changes in day to day operation. The interrelation of emissions and other engine control is a complex one. You may well find that your truck prefers the Fingers stick and a blocked EGR, or just leave it all functional and eat the soot. I've been playing a bit with this stuff on EFI Live and customizing things with pretty decent success. The thing to remember is that a change "here" can cause a reactionary change "there" when dealing with controls...