- Mon Jan 05, 2009 4:04 am
#87005
93_hatch wrote:ya i dont think i have a vac leak after looking into that today. how can i check my o2 sensor?
Before testing always make sure the car is fully warmed up and at normal operating temperature.
Hope this helps.
Testing With A Digital Mulitmeter:
Connect the voltmeter between the O 2 sensor wire and ground.
Backprobe the connector near the O 2 sensor to connect the voltmeter to the sensor signal wire. If possible, avoid probing through the insulation to connect a meter to the wire.
With the engine idling, the sensor voltage should be cycling from low voltage to high voltage. The signal from most O 2 sensors varies between 0 and 1 volt.
If the voltage is continually high, the air/fuel ratio may be rich or the sensor may be contaminated by RTV sealant, antifreeze, or lead from leaded gasoline.
When the O 2 sensor voltage is continually low, the air/fuel ratio may be lean, the sensor may be defective, or the wire between the sensor and the computer may have a high-resistance problem.
If the O 2 sensor voltage signal remains in a mid-range position, the computer may be in open loop or the sensor may be defective.
Testing ground:
If a defect in the O 2 sensor signal wire is suspected, backprobe the sensor signal wire at the computer and connect a digital voltmeter from the signal wire to ground with the engine idling.
The difference between the voltage readings at the sensor and at the computer should not exceed the vehicle manufacturer's specifications. A typical specification for voltage drop across the average sensor wire is 0.02 volt.
Now check the sensor's ground.
With the engine idling, connect the voltmeter from the sensor case to the sensor ground wire on the computer. Typically, the maximum allowable voltage drop across the sensor ground circuit is 0.02 volt.
Always use the vehicle manufacturer's specifications. If the voltage drop across the sensor ground exceeds specifications, repair the ground wire or the sensor ground in the exhaust manifold.
Testing o2 heater:
To test the heater circuit, disconnect the O 2 sensor connector and connect a voltmeter between the heater voltage supply wire and ground.
With the ignition switch on, 12 volts should be supplied on this wire. If the voltage is less than 12 volts, repair the fuse in this voltage supply wire or the wire itself.
BoRIcuA y QUE!
and i have rear quarter damage and a busted tail light.....
