2002 MAZDA MPV User Comment / Complaint

Engine was running rough and misfired. one dealer said this was a transmission module. after keeping it for several days and said the sparks needed adjusting, waited on the transmission module because it was running fine. then it stopped suddenly in snowy weather, towed, i was left stranded for 2 hours in cold weather, battery replaced, 2 months later it was running extremely rough and misfired. a new dealer said it was not the transmission module but the coils and all would need to be replaced for a $1,000. they said 3 were bad, but if they replaced those they would be back redoing the others with in a few weeks. car had 56,000 miles ,but was past warranty date not warranty mileage. this seemed to be what was wrong all along. i understand the catalytic converter might go due to this problem. i have heard that coils should not have to be replaced at this point.