My 2001 530i has been idling rough I took it in for diagnostics it threw out codes for misfire low fuel, multiple misfire, bank 1, bank 2, system too lean, idle air control system. When I pull the oil cap off there is a lot of suction, I heard it could have something to do with the intake but if anyone could help give me a place to start it would be a lot of help thank you
P.S. There is also some knocking coming from the engine I'm not sure if it's related, it happens about every 10 to 20 seconds
P.S. There is also some knocking coming from the engine I'm not sure if it's related, it happens about every 10 to 20 seconds