2.7t B5 RS4 missfire
 

Hi All, I have a 2001 B5 RS4 and it is running rough at idle, missfiring randomly during gentle acceleration and missfiring in a weird rapid consisitent rate when under boost. When under boost the feeling is sort of like a high rate pulsing slight backfire/vibration, sort of a similar sensation to ABS pulsing. Sometimes idle is very rough, as if it is going to stall. The car had fault codes for the exhaust temp sensors, but I have fixed those and cleared the codes, and they have not returned. No other engine fault codes have come up. The mechanic tried replacing the ignition module but it didnt help. The mechanic suggests trying a new set of coils and if that doesnt solve, getting injectors done. Any thoughts/tips/hints please?