Looking for some input, I have a 2006 Silverado 5.3L with the aluminum block. The truck has a K&N air intake and Flowmaster exhaust system on it. While under load or heavy throttle, the CEL comes on for mass air flow sensor. Is there a recommended upgrade sensor to install to fix this issue? I've tried cleaning it with no positive results.

What is the exact code?

I'm sure you know that K&N filters, with too much oil can contaminate the sensor....

^^^^^^^^^^What he said^^^^^^^^^

I have also seen on some occasions were an aftermarket air filter will cause higher than normal readings, causing the pcm too set the light on.

X3. Too much oil on filters can cause havoc on MAF'*.