I have a 2019 Silverado Custom. When I first got the truck, I did what 17 year old me always wanted and bought a K&N intake. About 3 months ago, I cleaned and re-oiled the filter but neglected the mass airflow sensor. It caused the check engine light to come on and throw a code for running lean in banks 1 and 2. 3 months later and it's still on and off. I took it to my mechanic who did everything short of a smoke test and said he hasn't found any leaks but mentioned that it could be that the sensor can't recalibrate because the airflow from the intake is greater than the stock one. Should I go back to the stock intake or look at an aftermarket mass airflow sensor?

 

I used to run K&N air filters in my vehicles until I took my finger and did a "white glove" dust test on the inside walls of the air handler that goes between the air filter housing and the throttle body on our 1999 Silverado and 1999 Buick Century. My finger tips came back with lots of dust on them. Dust that came through the K&N air filter. I immediately went back to premium paper air filters (such as NAPA Gold, PurolatorOne, Fram Extra Guard, etc.), cleaned the air handler and when I repeated the white glove test a few months ago, my finger tips came back clean.

Also, it is very easy to over oil the K&N air filters and the result will contaminate the sensor wire(s) in the MAF sensor.

My recommendation is to go back to a factory type paper air filter (it will filter much better) and get a can of MAF sensor cleaner and clean your MAF sensor.

You really will not notice any difference in engine performance because the Powertrain Control Module (MAF) will regulate the flow of gasoline based on the information it gets from the MAF sensor in order to keep the air:fuel ratio as close to 14,7:1 as is possible. Also, the O2 sensors will also report the amount of oxygen in the exhaust stream to the PCM which will then fine tune the amount of fuel it supplies to the combustion chambers.

I do not know how many miles you have on your Silverado, but if it is over 50,000 miles, you might want to consider installing new O2 sensors because O2 sensors do get lazy with age and mileage. My recommendation on O2 sensors is to go with either Denso or GM Genuine O2 sensors unless you want driveability issues.

Good Luck!

 

The same, bro