I just wanted to memorialize for posterity that it is now March 19, and the check engine light hasn't come back on.
My only conjecture on why the fault code came back on for a faulty transmission up shift delay valve after replacing the part is that the fault code was still stored in memory from before the repair.
In any event, I consider case closed on all check engine light problems (knocking on wood).
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Last edited by suginami; 03-19-2002 at 08:12 PM.