I have a 01 2500HD duramax. I have been tuning on gas cars/trucks for some time but this is my first diesel that I have ever messed with. I have a tune that I found online and pretty much copied it over to my truck. That tune seems to pull HARD but the shifting is all wrong it shifts very hard and flares between gears pretty bad. If I take off normal when it shifts into 2nd gear its like it goes into neutral then drops hard enough into 2nd gear to chirp the tires at about 30% throttle. It does this through all the gears at anything over about 10% TPS. It also down shifts hard when I'm coming to a stop you can feel it grab the next lower gear even at 0% TPS. Can someone please help the truck is 100% stock other than a muffler delete.
The hard shifting tune is mod-2.1 and the one that I have in the truck now is mod-2 and it shifts and drives just fine.
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