I have a 1999 prerunner 3.4 L V-6 automatic. Its been giving me a P0303 trouble code #3 cylinder misfire. Changed spark plugs, leads and swap coil pack with #5 cylinder and the problem is still on the #3 cylinder P0303 . I also changed fuel filter cleaned Mas airflow sensor. It appears that the problem is more noticeable at low rpm (vibration) at higher rpm very little vibration. Any advice.