my car engine has shut down 3time while driving and when i press the accelerator there is a sound like air while the engine going to shutdown.when i restart i can revs up then engine then shutdown back when i engaged the gear.my mechanic has check the airflow meter,changed new idle valve,rpm sensor,lambda sensor.even diagnos it but it shows no error.i having this problem for 2weeks still can't solve.this is the last place to check.hope someone can help me out.