The dealer's mechanic spent part of two days on the problem this week. At first the mechanic reported that both the check engine light and engine quitting were caused by the same thing, namely a vacuum leak. Later he reported that the problem was traced to "mass air flow sensor out of range". After making a smoke test and other checks he reported "Found wiring plug connecting air flow sensor binding. Repositioned harness. Rechecked wiring and mass air flow sensor operating correctly. Proper reading in system. Cleared code. Test drove vehicle to verify repair. No further code." The light is now out and the car appears to operate correctly. However, it seems to me that the engine controls are very complex and that it is probably difficult to debug problems. Any comments or suggestions will be appreciated.