A failing Chrysler oxygen sensor could result in poor gas mileage, failing an emissions test, hesitation, poor acceleration, surging, and more.  Every Chrysler built after 1980 was manufactured with an oxygen sensor.  The oxygen sensor's job is to communicate with the engine management computer to help the engine run efficiently and to keep the emissions as low as possible.  Every vehicle has a different "perfect" balance of air and fuel.  This ratio is dependant on the amount of hydrogen and carbon found in the fuel.  Your oxygen sensor is located in the exhaust pipe.  When performing properly, it detects lean or rich air/fuel mixtures and sends the information to the engine's computer where the amount of fuel can be adjusted to reach its perfect ration.  A mixture that is too rich is caused by too little air in the air/fuel ratio.  A mixture that is too lean is caused by excess air in the air/fuel ratio.  Replace a faulty oxygen sensor immediately to prevent damage to your engine.