Ok, my 2wd 05 Sierra CC is all stock except for 40 series Flowmasters right now. I eventually plan to upgrade a few things for better performance. One thing for sure is a Nelson tuned ecm, but I'm trying to find a way to come up with the 300 bones first. Until then, I have an issue. I've noticed that if I stick the throttle to the floor from a stand still(dig), the ecm doesn't let the engine rev up enough and it just has a very slow take off until about 25-30mph when it finally picks up a little rpm and starts to rev better. Is there any way to fix this without a full custom tune?