16684 fault rough idle
 

ok, so i spent alot of time checking forums, and have tried a lot of stuff..
changed plugs, ran injector cleaner, swapped out coils (switched 2 to 3 then 4 to 2, then 1 to 3, ect. no clue what originally goes where, but same code, misfire on 2) cleaned a couple valves, and i'm stuck til i can hit a dealership to try getting new boots. is there anything else i can try?

*note* plugs look a little bit on the white side. dealer claimed there was a ecu upgrade, then later when i got it home i found the n75 valve not attached. is it maybe over chipped?

changed boots now, still rough idle. same code.


btw car is 1999 1.8t 5sp manual