Presidents Day 1999

Name an auto part a little bigger than your thumb which, when it fails, can cost you about 6 tanks of gas a year. If you answered the oxygen (O2) sensor, go to the head of the class. It's the subject of a new pamphlet explaining this critical role this part plays in your car's driveability. Producers of the literature, BWD Automotive Corporation, say if your car is a 1980 model or newer, it has one or more 02 sensors. Further, according to Larry Yeager, Director of Training at BWD's Engine Systems Learning Center, if your vehicle has been running poorly and using more gas than it used to, a malfunctioning O2 sensor could be the culprit.

"This device, which is located in the exhaust system, measures the amount of oxygen in the exhaust," explains Yeager. "Optimum ratio is 14.7 parts of air to 1 part of fuel.

This critical mixture can be affected by something as simple as a dirty air filter or a faulty spark plug. Either of these, as well as many other engine deficiencies that affect exhaust emissions, are detected by an oxygen-sensitive ceramic element, the heart of an 02 sensor. When the fuel-air ratio is out of balance, the sensor signals whichever computer controls the malfunctioning system and corrective measures are taken."

This incredible "sense-signal-correct" process can happen many times a second and, when everything is working properly, emissions are reduced to acceptable limits. When there's a malfunction, most often because of a sluggish or non-functioning 02 sensor, performance deteriorates and emissions increase. The condition also can seriously damage the catalytic converter, a critical part of the emissions control system.

Typical replacement cost: $300 vs. about $80 for an oxygen sensor that might have prevented the trouble in the first place. Not surprisingly, the neglect that often leads to high exhaust emissions also may have affected the 02 sensor, which also deteriorates with age. For this reason, experts recommend that the 02 sensor be replaced periodically as part of the preventive maintenance process.

"Consumers should be aware of the importance of this component," concludes Yeager. "Most vehicle owners don't even know the 02 sensor exists, much less that it is a replacement item."

For more information on this subject ask your ASE Certified Technician or send for the company's free pamphlet. The address is Literature Department (re 02 sensor pamphlet), BWD Automotive Corporation, 11045 Gage Avenue, Franklin Park, IL 60131.

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