My 1994 E320 wagon recently provided that chilling "check engine" message that is most disturbing to one's financial well being. After a visit to the local dealership, the diagnosis was-failing smog pump and computer. After opting for the $900 smog pump replacement and passing on the $1700 computer replacement, the car ran just fine (same as before the pump replacement). After about three weeks, the dreaded "check engine" light was once again illuminated. The car still runs great, but I am concerned. Is continuing to ignore this message a catastrophe waiting to happen, or a nuisance provided by a conservative manufacturer? Can the "check engine" light be reset without going to the dealership? Is this computer replacement even a credible diagnosis? Any suggestions?