Problem started if im running cruse control, when i go down hill and decelerate the converter unlock, no codes, but if i force clear computer it locks back up instantly. So i go to the trans shop. They said trans is in great shape everything is right, but have 2 cylinders misfireing and low volt on mass air meter, i replace the mass air meter, new injectors, msd coil packs, and a set of taylor plug wires, if im in park and hold the motor at 2500rpm for a min, light comes on for p0300. What can it be? Gonna change plugs today, but there only couple months old.