ML 320 2001, 130k miles: Chasing Gremlin-Help! Codes P0100, P0170,P0173. Intermittent rough idle, about every 6-8 times at a stop in gear, place in nuetral and runs fine. So far: Spark Plugs, Plug wires, Air filter, fuel filter, trans connector plate, EGR, MAF (aftermarket now MB). Checked extensively for vacuum leak-none, multiple fuel injector cleaners. Does not change good engine idle when I un-plug MAF sensor connector? Now; during fast accelorating, missing, shifting late. I am now thinking fuel pump? What should the pump output pressure be? Test with guage at the rail? Any other thoughts?