For a free test, you may want to give the EHA a small turn....I had a number of bottom end problems on my 260E that were completely resolved after I gave a 1/2 turn clockwise (rich) on the EHA. I recommend you write down exactly how far you turned and mark it so if you need to turn it back, it won't be a problem. Giving a 1/4 or 1/2 turn will raise BAR pressure in the lower fuel distributor chamber that just makes up for general wear and tear over the years throughout the system.

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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