Okay, first thing is there is no way to "clean up" and 0/2 sensor. If he put any sort of chemical at all on the sensor, he has likely ruined the sensor and it will have to be replaced.
You have a lean code that we do not know if it can be believed or not due to the unknown condition of the 0/2 sensor.
I would check for any tears in the intake snorkel or lines left off that would introduce un-metered air into the system after the MAF. You can also clean the MAF wire with MAF cleaner.
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Wednesday, August 30th, 2017 AT 10:25 AM