My 1999 MBZ E320 4motion wagon. 104,000 miles. The Check engine light comes on, OBD, says 703 MAF sensor. Replaced with new one. 30 miles, light comes on, car goes to limp mode. I make it home, OBD same issue. Clean MAF. Car runs fine. When going from speed to idle, light comes on again. It seems OK at speed but, like my horse, doesn't want to slow down.

Any fix suggestions?

 

sounds like vacuum but this is a quick easy diagnostics go to a local parts store and get a vacuum tester for $20. or so plug it to any line leading to the intake manifold should of course read in the green zone of the gauge 15 to 18lbs. If you need help after testing let us know.
patch's