I recently took my c230K Sport in for a 'B' service. The car has about 42k miles. In addition to needing new brakes & rotors on both axles, the car needed new front lower ball joints, transmission work(valve body work and new control module) and a new mass air flow sensor. I am somewhat concerned about the air flow sensor. What could cause a problem that would require replacement at on 42,000 miles? This was done on warranty as was the transmission work, but I am still concerned. There was no sign of this such as check engine light, fuel economy drop off or hard starting. I have never had to replace this even on my American cars. From another thread on this board, it sounds like it could be an expensive repair. I have kept to the factory maintenance schedules. The transmission work is somewhat troubling too...

Thanks for your help. I am a new member and this is my first post. This is a great site!