I lived through a plenum failure on my '94 sr (after replacing the motor) and I never had a check engine light. That is until the engine seized.

Did you plug it in to a code reader before you took it apart? You might have another problem besides the vacum leak.

By the way, the only symptom I had prior to engine lunching was a wistling sound that I thought was coming from the a/c vents.

On a final note, I live in Ventura county & have a scan tool that works on both pre and post '96 Mits. It would be nice to know who else has similar units, and setup a sort of code reading/diagnostic network.

Clark