I have a 06 GP gxp. I had the plugs replaced and did a few tranny flushes trying to fix the issue, not knowing what the problem was at 1st. But when the throttle is pushed like 5-15% the car feels like it's misfiring pretty bad. The motor shakes. It's never kicked a misfire code or had the check engine light go on. I believe it's the DOD turning on and off. When I put it in 3rd in manual it disables and is fine. What should I do to fix the problem when the car is in automatic?