P1087 Buick Exhaust Bank 4- Mixture Adaption Range 1 Lower Rich Limit Not Reached

P1088 Buick Exhaust Bank 4- Mixture Adaption Range 2 Lower Rich Limit Not Reached

Possible causes
– Faulty Oxygen Sensor
– Oxygen Sensor harness is open or shorted
– Oxygen Sensor circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
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