I have a 09 chevy crew cab 4x4 6" lift 20x12 wheels withe 35's and I put a programmer on it and it has no pulling power it struggles pulling a 6x10 trailer with a atv on it. What could I do to fix that?

 

If you want to do it right, it's gonna cost a lil bit of money. New gears front and rear, vette servo/shift kit for the transmission, take that programmer off and do a custom tune. If you want more add Longtube headers, and cam it