Thumping sensation under spark plug wire 2 and 3? Any reason why? You can hear it too. When you press down on them, the sound and the thumping go away.
Car is also sputtering sometimes. Air / fuel goes lean and then rich too.

 

found that the 2nd and 3rd spark plug were loose, really loose. I replaced all of them and the engine began running the way it should. Thumping sensation went away too.

 

found that the 2nd and 3rd spark plug were loose, really loose. I also noticed that the spark plug wires could not seat all the way down like they should. I replaced all of them and the engine began running the way it should. Thumping sensation went away too.