I have an ML320 with 65,000 miles, 2000 model. Once every couple of weeks, when I first started up the ML, it would bog down. When I turned the key off, then back on, it would then run fine. This vehicle has been very well maintained. I was advised it could be the catalytic converter or the MAS sensor. In the meantime, it was recalled to have the catalytic converter replaced. After having this done, the problem is actually getting worse. It does it all the time now, until I get up my speed. Do you think I need to replace my MAS sensor, or what?