You only have one fuel pump on your 260E....

Have you thought about the possibility of the precats being plugged? Are you losing any oil? I had the same issue one night when I was driving and the car just would not accelerate at all. Pulled over and my precat was glowing purple...Let her cool down and didn't happen again...but just a thought for yourself maybe?

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k