I have been getting the PO300-PO306 codes which is missfire. Plugas and wires have been replaced. I also get the PO170 & PO173 which is fuel rail. My dealer say MAS is the problem. I dont mind replacing but hate to if i just taking a stab in th dark. Also under accelleration is missed very bad and almost get runover in traffic. I know that if there is substancal missing that the tranny will go into "limp mode" for protection. I have a OBDII scanner and reset the codes and now a new one has popped up...PO715-"Input/Turbine spped sensor A circuit malfunction".

Here's the question:
PO715-Is this transmision related and can the MAS be causing engine to run too lean and causing missfire and irratic transmission shifting? I have 180,000miles and is a 1999 ML320.
help is appreciated before all hair is yanked out!