The Brick Newsletter September 2010

Oxygen Sensor Testing

The sensor produces a small voltage based on the oxygen content in the exhaust relative to the outside air. When the mixture is lean the oxygen content is high and the voltage is low. When the mixture is rich, the voltage is higher. The voltage can be measured with a voltmeter capable of measuring with a minimum of 10 mega ohms impedance. Do not use a meter with less, as it may damage the ECU.

Connect the positive test lead to the oxygen sensor and the negative lead to ground. Start the car and warm it up to operating temperature (the oxygen sensor does not work until the temperature reaches 600 degrees).

Note: Leave the oxygen sensor connected, and probe through the rear of the connector when connecting the volt meter.

At idle the oxygen sensor should be between .04 and 1.0 volts. The voltage should fluctuate. This indicates that the sensor is working. If it’s steady or there’s no voltage, the sensor is probably bad. Another, less accurate, test is to simply disconnect the sensor when the car is running; if the idle fluctuates after about 30 seconds, plug it in again and the engine should fluctuate again until it smoothes out the idle. If no change occurs, then the sensor is probably bad.

Mass Air Flow Sensor

Mass Air Flow Sensor Cleaner

CRC Mass Air Flow Sensor Cleaner is the safe and effective alternative to “underground” methods of MAF sensor cleaning. Don’t use aggressive chemicals like brake parts cleaners or carburetor cleaners on MAF sensors. These can cause serious damage to sensitive parts. Use CRC MAF Sensor Cleaner -- It’s the right product for the job! It safely and easily cleans the MAF hotwires and electrical components without damage to the wires or plastic housing. Cleaning is simple, safe and fast. The whole job should take less than 10 minutes! Mass Air Flow Sensor Cleaner benefits and features:

• Safely cleans and protects MAF Sensors Plastic-safe and leaves no residue
• Increases horsepower Decreases hesitation and pinging
• Improves fuel economy and MPG
• Reduces rough idle

Use every time you clean or change your air filter.

Lambda/Oxygen Sensors Reduce Emissions

An oxygen sensor allows your engine to run as smoothly as possible, because it measures the exhaust gases and relays information to the fuel system control unit. With this information, the control unit can fine-tune the fuel mixture for optimum fuel economy and power. A dead oxygen sensor can also lead to significant idle and performance problems.

Oxygen Sensor Wrench