I had a smash up that broke the air intake filter box 95 E320/ M104, and found the car wouldnt run without the filter installed. It seemed to need the intake resistance of the filter box/filter to have a steady idle and without it connected, it surges and dies. Could possibly be a vacuum leak back behind the MAF sensor at another joint being affected, and I misdiagnosed..who knows. but if you do need some intake resistance..ram air would mess that up totally. Your system may vary, not familiar.