I would take it to another tech. Did he try to disconnect a sensor to see if the system can produce a code? Did he do a test to see what is causing the misfire? Is his scan tool any good? There are to many questions to provide an answer.
Conner


Over the hill but still climbing.
88 Montero 2.6L auto, manual hubs, cooling fan conversion gps,recurved distributor,LSD Diff.