Thanks for your response....I've also heard that a bad O2 sensor can cause a loss of power? I still haven't replaced mine yet (since the car was new)....i.e. the O2 sensor has been used for 245,000 kms!! (It's supposed to be changed at 96,000 kms, but I didn't change it.) Could the O2 sensor be the problem? Also, can someone please give some pointers on how to replace it? I know it's made by Bosch...but the MB dealer wants CDN$150+labor. I've heard that the 1990 Ford Mustang V8 uses the same O2 sensor and someone has actually used it in an MB and it worked flawlessly. Can someone verify this?

Thanks in advance.