ok on the drive home tonight from work i was going home and the trans started to slip so i was like **** must be low on trans fluid so i pull over check it and its full so i jump back in and get a mile down the road and it starts slipping again so i let off on it and it starts to move good so then after keeping it under 4grand the rpms seem to go down and the motor sounds and feels like it wants to stall like its dieing down and then it will go back to normal. what could make this happen. it has a 3600 yank and long tubes and its untuned. when it was loosing rpms it made a sound like gariling or something.