Later model Fiat and Alfa Romeos have an oxygen sensor in its exhaust system. You may never have encountered an oxygen sensor or know what it's used for, but it's a part that requires periodic replacement. Otherwise, you may experience poor vehicle performance.
Oxygen sensors are designed to measure the oxygen content of a car's exhaust gases. This information helps the engine-control computer regulate the mixture of air and fuel burned in the engine to provide an optimal balance of power, economy and clean exhaust.
Oxygen sensors are relatively simple to replace, with most models costing from $50 to $100. Replacement intervals range from 50,000 to 60,000 or more miles, and are generally referred to in the owner's manual.
You may not notice a difference in the way a car drives with a defective sensor and assume that nothing needs to be done until the car "acts up". This can be a mistake, as an engine may use more fuel when the oxygen sensor isn't working. This hurts economically and creates dirty exhaust, polluting the air. Testing and replacement your car's oxygen sensor at recommended intervals assures trouble-free driving.