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Home >> Chevrolet >> 1990 >> Caprice Base, 5.7 7 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 4.3L TBI >> Pcm/BCM Code Charts >> Code 45, Rich Exhaust Indication >> Test Number 1)

Test Number 1)

Test checks to see if O2 sensor is registering a rich condition. Code 45 is set when vehicle is at operating temperature (in "closed loop"), throttle angle is greater than idle, O2 sensor signal at control module is greater than .7 volt for a precalibrated period and time since engine start is one minute or more.