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Home >> Toyota >> 1991 >> Corolla Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 4-CYL >> Code Charts >> Code 21, 27/Test No. 4 - O2 Sensor Signal
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Code 21, 27/Test No. 4 - O2 Sensor Signal

NOTE: Code 27 applies to 4A-GE only.
Fig 1: Code 21/Test No. 4 Schematic (4A-FE) O2 Sensor Signal
G91I17770Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Code 21/Test No. 4 Flow Chart (4A-FE) O2 Sensor Signal
G91J17771Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 3: Code 21, 27/Test No. 4 Schematic (4A-GE California) O2 Sensor Signal
G91A17772Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 4: Code 21, 27/Test No. 4 Schematic (4A-GE Federal) O2 Sensor Signal
G91B17773Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 5: Code 21, 27/Test No. 4 Flow Chart (4A-GE) O2 Sensor Signal
G91J17722Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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