nissan Workshop Repair Guides

Nissan and Datsun Workshop Service and Repair Manuals

Oxygen Sensor - Thread Cleaning and Other Precautions|Page 3570 > < Oxygen Sensor - Thread Cleaning and Other Precautions|Page 3568
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Catalytic Converter: Description and Operation

ON BOARD DIAGNOSIS LOGIC 
ECM monitors the switching frequency ratio of front and rear heated oxygen sensors.

A three way catalyst with high oxygen storage capacity will indicate a low switching frequency of rear heated oxygen sensor As oxygen storage capacity
decreases, the rear heated oxygen sensor switching frequency will increase.

When the frequency ratio of front and rear heated oxygen sensors approaches a specified limit value, the three way catalyst malfunction is diagnosed.

Oxygen Sensor - Thread Cleaning and Other Precautions|Page 3570 > < Oxygen Sensor - Thread Cleaning and Other Precautions|Page 3568