FIY auto oxygen sensor

[bkuhr]

Just read interesting article about oxygen sensors. Did not know about rear access to ambient air, and need to keep the 'normal' gunk off the sensor.

 

Automotive Trivia

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The core of a typical oxygen sensor is a zirconium dioxide (zirconia) ceramic. Oxygen ions flow freely through this ceramic after it is heated to 600 deg. F (316 C). What else is zirconium dioxide used for?

A. imitation diamonds

B. thermal barrier coatings for diesel engine parts

C. foundation for dental crowns

D. all of the above

Answer below

 

 

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The Other End of the Oxygen Sensor

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Oxygen sensors thread into the exhaust system where they obviously face extreme heat and harsh exhaust gases. Oxygen sensors fail when the bulb inside the exhaust pipe is exposed to lead, silicone, antifreeze, engine oil and other contaminants. Many people are not aware of the role that the other end of the oxygen sensor plays. Surprisingly, the visible end of the sensor with the wire pigtail is just as important and sensitive to contamination as the end slugging it out in the exhaust pipe. Nearly all oxygen sensors are designed to measure the difference between the oxygen level in the exhaust with the oxygen level in the outside air. The sensor generates a voltage based on the difference in oxygen levels that the engine computer uses to continuously adjust the fuel mixture, etc. The outside air the oxygen sensor needs for its comparison enters the sensor at the end with the wire pigtail. Depending on the sensor design, the air might enter through a dedicated hole or through the wires.

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The oxygen sensor ambient air inlet is likely to be protected by silicone boots, porous PTFE (Teflon) or some other means. A routine splash of water is not likely to hurt an oxygen sensor, but leaking chemicals (engine oil, power steering fluid, etc.) can clog or enter the oxygen sensor air inlet and damage the sensor. Efforts to “protect” oxygen sensors by spraying them with lubricant, covering them with insulation, etc. can backfire if the sensor’s air inlet is blocked or contaminated.

Oxygen sensor installation instructions emphasize that the entire sensor, including the wiring harness, is part of an integrated system. Routing and connecting the wires is as important as carefully threading the sensor into the warm exhaust pipe. I just read installation instructions for a Bosch oxygen sensor that had just two steps covering removing the old sensor and screwing the new sensor into the exhaust port. The instructions had ten steps covering the connection and routing of the oxygen sensor’s four wires.

The oxygen sensor bulb buried in the exhaust pipe is on its own, but you can maintain the other end by making sure the wiring harness is never torn, rerouted or covered with goop.

Tom Taylor,

RockAuto.com

[Scooter Bob]

If all this O2 sensor for accurretly setting fuel mixture info is on the web...

 

WHEN WILL YAMAHA FIGURE OUT HOW TO USE THE INFO TO GET RID OF CARBS!!! LOL

 

Later, Scooter Bob

[Guest]

I had to change my oxygen sensor last summer on my Chevy Trailblazer. It was running real rough, even after the plug change at 115 thousand miles. I took off the throttle body and thoroughly cleaned it and replaced the o-ring, which helped a little. I bought an OB scanner and discovered the bad o2 sensor. Luckily I had only one to change. It was a Bosch that I used and you need a special socket to remove and replace so you dont screw up the wiring coming out of the tip. Also use anti seize compound on the thread when installing. From my reading up on these sensors, the best time to change them is at about 75 thousand miles. Like the above article says, it lives in a real nasty environment. Any higher mileage then there is a pretty good chance that the sensor will be real stubborn to get out. Mine was since there was about 115k on the clock and it was pretty frozen to remove. I had to get the socket sitting square on the sensor, start the motor to get the sensor and exhaust hot, shut it down, then slowly turn the sensor. It cools down pretty quick. I had to run the motor at least 2 more times to loosen it up. Been running fine ever since. I also had ordered the downstream o2 sensor but that rarely goes bad. One day ill install that as well.