I have a '97 E300D with 265,000 miles and have tried to keep the engine well maintained. However, for the last 8-10 months it's been shifting like it should when cold. It will run all the way out to around 5,200 then shift without having to lift my foot off the pedal. It will only do this for 3,4 shifts the it falls flat on its face at around 4,300-4,600 rpm. If I stay on the pedal, the car will just hover in that range. the only way to change gears is to lift my foot from the pedal and it will shift.The next gear will do the same thing till I get to overdrive and traffic speed. The kick-down (passing gear) does no good since it will stay flat once engaged, so it's better to time my driving to blend with traffic without needing it. There's a feel of running out of go juice when this happens, like it's starving for fuel or air. I try to do all my own work but since I only have a OBD 2 reader the only DTC I get is a PO400 "exhaust gas re-circulation flow". I've cleaned my EGR valve & replaced all vacuum lines to said unit and the EGR solenoid valve assembly. I'm beginning to think it may be my throttle positioning sensor assembly but don't know how to test it...Please, if someone has had this problem before, I would greatly appreciate any help. Thanks!

 

Hello and welcome to the forum! Take a look at the link below to an earlier thread where the TPS is discussed. Hope it helps you troubleshoot.

96 E300D TPS Problem - PeachParts Mercedes ShopForum