Found a broken vacum line to the intake pressure sensor on my E300 snipped off the bad part and reinstalled. Ran great for about a day and a half. Then CEL came on and the car began surging and stalling worse than ever. The surge that is not unusual at 35 and 50 MPH was surging all the time. Called the shop I have bought some parts from and got it in to check the continous CEL. Looked under the hood just before the drive over and found the intake pressure sensor vacum line completely off. replaced it this time and went onto the shop so they could check codes. Only code was the intake pressure sensor they checked all parameters and cleared the codes test drove and told me that the hose being off was probably the probelm. I am waiting for my wife to get home from work to see how the car ran. It will be great to have that as the only thing causing all the problems. Fingers Crossed.