management and idling?Thanks!? My car's engine shakes a lot (rpm goes down to 600 or less) when the A/C is off, but the shakes go away once the A/C is turned on (because of the higher idling speed I guess). Also, whenever the accelerator is stepped on, sometimes the engine doesn't react instantly: there is a lag of about a second or so. Local BMW shop already replaced a crimped rubber hose but the car still shakes. The shop's computer could not locate any problem other than the broken ASC sensor (which I already know is busted because it appears on the dashboard warning lights). They've already reset the codes to erase the fault, but the shakes+lag+the dashboard warning lights are still on. Could the "shakes" and the lag be attributed to the busted ASC-DSC-ABS (?) module/sensor? Any one have an idea what else could cause the shakes and lag? Thanks, much obliged!