This is what happened on my wife's car. '94 C280. The car was just started and it backfired. Then it idled rough and the brakes are minimal. If it was on some other car I'd say that the backfire caused a vaccum line to come off. The car has over 150k miles on it. After reading a bunch of threads it seems it may be the MAF/air mass sensor. I'm going to recheck the sparkplug wires, coil wires and everything in general. Prior to this the engine would die or act sluggish going into turns. Sometimes it would die in traffic but would restart with no problems like it needed to be rebooted. Any suggestions.