Z4 help idle lunges and won't rev

Help, My 2003 z4 battery died. I charged it and started the car but it will only lunge in idle and engine won't rev at all. strong gas smell coming fron exhaust.

Ok, I unplugged battery from the car and continued to charge it. Today I hooked it back up and the car ran fine except the service engine soon light is on. How do I wipe the codes so I can see if there really is something wrong or if this was just from the battery having a low charge?