I cleaned mine and it worked great for about a week before acting up. I cleaned it again with no improvement. Same flat spot, would hesitate and stall unless I accelerated either very slowly or very aggressively. I keep the old one in the trunk as a backup in case of total failure - it may not work great, but it does still work.

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280