I have a '99 528i running really rough. It even backfired a couple of times when cold. Current codes are p0170, 0173, 1188, 1189, 0300, 0302, 0306. I know the first 4 are fuel trim related and the other 3 are misfire codes. I just don't know where to start looking. Could the misfires be caused by the fuel trim problems? Any help would be greatly appreciated.