Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

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LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Oxygen Sensor: Testing and Inspection

OXYGEN SENSOR TESTING
A Tech 1 scan tool has several positions that indicate the state of the exhaust gases Oxygen Sensor (O2S) voltage, short term fuel trim, and long term fuel trim. A fault in the O2S circuit should set a Diagnostic Trouble Code (DTC) 13 (open circuit), DTC 44 (lean exhaust indication), or DTC 45 (rich exhaust indication).