Oxygen sensor on vehicle.
The oxygen sensor was located on the top of exhaust manifold and is a four wire sensor.
Wire colour Blue- Signal
White- Heater
Black- Earth
Black- Heater earth
Make the oxygen sensor go rich then freeze the pattern. Note how high the voltage goes.
Make the oxygen sensor go lean. Freeze your pattern and note how low the voltage goes.
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Measure the response time of the sensor freeze your pattern and note how long it takes to go from lean to rich.
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The Zirconium oxygen sensor
The Zirconium dioxide sensor compares the amount of oxygen in the exhaust gas against the oxygen in the atmosphere. The sensor has a (ZrO2) zirconium dioxide element that is set between two platinum electrodes. The two platinum electrodes act as positive and negative plates and the zirconium dioxide element acts like the electrolyte all together they act the same as a single cell battery. When there is a rich air/fuel ratio the inside plate has much more oxygen than the outside plate. The electrons will flow through the Zr02 element to the plate with the most oxygen content this creates a voltage which is measured by a comparator circuit in the ECU.
The oxygen sensor I tested on the toyota corsa worked well, because it has a heater I didn't have to wait long before it went to closed loop. When I reved up the engine the voltage went up to 0.8v which showed a rich mixture. When I decelerated the voltage dropped down to 0.1v showing a lean mix and it was very quick to respond to the fast acceleration approx 0.1ms.
WS7 Exhaust Gas Analysis :
Record the four gases with the probe sensing normal air.
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Place the probe in the exhaust pipe and record the four gas readings.
CO - 0.001 [%vol] because this is normal air
HC - 7 [ppm] this means theres 7 parts per millon HC in the atmospher near the analysiser this is a very low reading.
CO2 - 0.00 [%vol] no co2 in normal air
NOx - 0 [ppm] no NOx in normal air
Record the four gas readings with engine idling cold.
CO - 0.423 [%vol]
HC - 472 [ppm]
CO2 - 13.80 [%vol]
O2 - 1.75 [ppm]
These readings show the engine has not warmed up the HC's are quite high showing a rich air/fuel mixture CO2 and O2 are ok.
When the engine has warmed up, record the four gas readings :
Explain what is happening within the engine referring to the four gases :
CO - 3.76 [%vol]
HC - 705 [ppm]
CO2 - 3.45 [%vol]
O2 - 3.65 [ppm]
When the engine has warmed up, record the four gas readings :
Explain what is happening within the engine referring to the four gases :
CO - 3.76 [%vol]
HC - 705 [ppm]
CO2 - 3.45 [%vol]
O2 - 3.65 [ppm]
The CO's have decreased this was expected but HC's went up to 705 ppm and CO2 droped to 3.45%vol
this indercates the catilitcic converter was not operating yet. This is because HC's should decrease to below 100ppm but they increased to HC's at 705ppm. This means there is a rich air/fuel mixture.
this indercates the catilitcic converter was not operating yet. This is because HC's should decrease to below 100ppm but they increased to HC's at 705ppm. This means there is a rich air/fuel mixture.
