exbanker

My 2001 Toyota 4runner stall occasionally. It seems to happen when it rains or snows. The check engine light does not come on, so the dealer can't pull any codes. We have changed the fuel filter, air filter, cleaned the fuel injectors and cleaned the mass air flow sensor. We took it to the dealer. They cleaned the mass air flow sensor again. The 4runner stalled today with wet weather. It stalls then restarts itself as we shift from drive back through neutral to park, has restarted in reverse also. The mechanic doesn't think it is the starter or the starter relay. Without codes we don't know what to try next. Please help!