hey sdgtp99 my gtp is supercharged i havent see a gtp that isnt supercharged and no my tranny is not busted,i mean that the car is rolling at 35or 40 mph and you punch the gas it suposed to down shift to closet gear. isnt that the passingear for? well my car does all of that but is kind of weak. doyou think that da cat is clogged?