Alright i dunno what this problem could be and i've asked quite a few people and i havent got a solid answer. Alright say im driving on the highway and i decide to downshift into 3rd or 4rth, now mind that this does not occur evertime, all of a sudden the car will just buck ! between like 3-4000 RPM. I dunno what the problem could be, my friend mentioned fuel cut-off. Does anybody have an answer for me! This has been a problem thats been bothering me since i purchased the car. PLEASE REPLY!