backfiring problem!!!help
hopefully some one here can help,ive got a serious backfiring problem going on with my s2 turbo,recently had engine rebuild but was misfiring,changed the spark plugs and set gap to 30thou and now its deciding to backfire but only from 3rd gear upwards and when you boost,it also cuts out whole engine whilst driving for a few secs...anyone got any advice the only thing i cant hink off is maybe the gapping?????