Just did a trans oil and filter change as well as a tune. i now have a random problem. When driving, as the trans shifts uo to 4th then i decelarate and when i go to lightly push on the throttle, i get no response....In other words the motor doesnt rev nor the trans. It acts like there is a dead spot. Its happens usually between 30-50 mph when decelarating. PLEASE HELP!!!!