Mazda Repair: Engine Cutting Out, oxygen sensors, faulty sensor

Question
I own an 1993 Protege DX. Car will cut out at highway speed and may also sputter and stall at idle. Problem is very sporadic (once every 2-3 days). Sometimes check engine light comes on before it happens, sometimes it doesn't. I had full tune up performed and replaced plugs, wires, rotor,and fuel filter. I had idle and throttle adjusted. I had dealer run diagnostic: result was bad oxygen sensor.Dealer told me this wouldn't cause this problem. I'm stumped and frustrated. Any ideas????

Answer
Well you can go back and tell the dealer that they don't know jack. If a sensor were to fail on a vehicle it would cause the vehicle computer units to go into a closed loop at WOT and stay like that. The results of a sensor failing are the stalling, sputtering, dieing out,the vehicle uses up way more gas than it normally does. Don't replace anymore of the vehicle's parts except for that faulty sensor. I knew what it was even before you told me that it was a sensor. The sensor failing is nothing unusual though so don't worry about that Oxygen sensors are the one's that fail more than the other sensors mostly because of the exhaust. One thing though before you were to go out and get a new sensor or have it replaced just chech the connecting points on the sensor and it's wiring, then just check the wiring to make sure that it's ok also and you can just check these visually.