hi, this is my first post, so i bought a 08 Grand Cherokee with the 4.7 liter engine about 2-3 weeks ago, the jeep is running ok but when im trying to get onto highway, i step on the gas and the jeep doesn't want to go anywhere, the rpms go up but the jeep doesn't really go anywhere until i hit about 2500-3000 rpms and then it takes off. i know something is wrong so i took it back to the dealer and they said that its normal and its all electronic so its going to take a min for the jeep to respond. there was a recall on the final drive control module, so they reprogrammed it and it seemed to work for a day or two but still have problem. Any idea whats the problem, any input will help !?!