hi there, my battery recently went dead on my audi whilst i had it off the road as i did some paint work on it , after jumping it with my booster pack the car started idleing at 1500 revs and occasionaly jumping between 1500 and 2000 my inital thought was to check and clean the idle valve which i did and also clean the throttle body after which it was still the same, so i then plugged in my computer and it was just a matter of resetting it and clearing some codes hope this helps anyone that may have this problem after there battery losing charge