Your knowledge about the 500E is impressive. My car was build 7/2/92 and delivered 4/22/93. I went a get a second from a trustworthy MB mechanic this morning. He put the diagnostic tester and checked out the fault. It indicated a air injector fault. He said that if it was his car he is not even worrying about this. He resetted the light for me. He also said that the air injection system (particularly the pump) is only used for about 15sec upon cold start up in the morning. He suggested that he'll take care of this problem when car has about 150K miles where he will install new guides, chain..... So for now i am going to ignore the problem. The wire harness concerns me a little though. BTW my car idles fine in the morning.