I have had a problem with my W202 for a few weeks where in the morning, especially when it is cold it mis-fires a lot and there seems to be a complete lack of power until the car warms up. Having read some threads on MAS problems I disconnected the MAS unit (un-clipped it) and like magic the car seems to be transformed. No more mis-fires and performance is like it used to be before the problem started. If I reconnect the MAS the problem comes back. My question is, why should I replace the MAS unit? Can I simply not leave it disconnected. Can anyone help.