Had a thought, are your still having that problem? If you are it might just simply be your stillen intake hitting the side of your strut tower or wheel fender. Cause when i first put on the same, the whole piping and airfilter was loose, so everytime i step on the gas you would hear a knock or a thump against the strut tower, and the harder i'd hit the gas the louder the thump... It could be something that simple! worth to check- not sure if i'm totally off though...