I have a 2007 335i and am getting misfires in bank 2, cylinders 4, 5, and 6. Coils and plugs are new(er). Swapped them around anyhow and misfires stay in bank 2. Just swapped out all fuel injectors. Bank 2 lambda was out of tolerance so I swapped the upstream bank 2 O2 sensor. Still getting a misfire on bank 2, all three cylinders. Now what? I suppose I could have received a bad O2 sensor, but is there anything else to check before that PITA? thanks!