Hey guys, you do not know how much appreciate the responses. It very well could be the vibrations at that speed and I will attempt to wiggle some components to see if there's a change in the idle. It drives fine until around 85mph. I've even went to WOT from around 20 mph and it did not misfire. I awaiting a new MAF and MAP and will update once I replace them. I performed another vacuum test, this time looking for back pressure. According the test, there was none.


Here's the fuel pump I purchased in May 2017 from fcpeuro.
Mercedes Electric Fuel Pump (300CE 400E 500E) - Pierburg 0004707894
I could not find where I purchased the fuel filter. I think I purchased it local. It was a Mahle. Could it be the filter? I purchased a cheap one on rockauto and it destroyed a fuel pump. When that happen, the pump hummed really loud and the car would stall when I came to a stop.