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Trouble Code 21 - Oxygen Sensor

NOTE: For Trouble Code 21, Figure and Fig 1 , if the O2 Sensor voltage is above 2.5V w/engine running, repair the fuel system for rich or lean condition.
Fig 1: Trouble Code 21, Oxygen Sensor Part 1 of 2
G42158Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Trouble Code 21, Oxygen Sensor Part 2 of 2
G42159Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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