Vehicle will not start or idle falls vehicle, Mazda3 manual, would not start in driveway on cool spring Sunday evening. Towing service was dispatched and vehicle was taken to the closest Mazda dealership. After several dealers calls to Mazda's corporate headquarters, the service professional was told to replace the ignition key and microchips. After four days I went to pick up the vehicle. Upon starting the vehicle in the dealers lot the idle began to fall once again; however, it did start this time. A few miles from the dealership the idle became so hard to deal with that the vehicle was towed back to the original service dealership once again. Several more calls were placed to the headquarters and finally the decision was made to replace the O2 sensor. The car has started and run ever since the repair, but the idle is much lower than it was on original receipt of the vehicle, and the engine at idle speeds is much louder and sounds labored. Once winter comes I fear the problem will reappear. The future of the vehicle's performance is unknown. Possible safety compromise.

- Oil City, PA, USA