I kind if wish I didn't take mine out. Haven't noticed any difference but some of that stuff you wrote makes sense. I heard about doing it from a radio answer guy-mechanic-shop owner who's also a big-time bow tie lover.

 

i can't swear to it but i think my screen out might be the reason i am running rich. or at least dumping fuel. as always, i am looking for a spare screen lying around if anyone has one.

 

That is exactly what I was going to say!

 

I've got an extra MAF, so I tested one without a screen recently. I noticed no real increase in performance. Only change was it threw off my LTrim fueling at low flow values. Basically its seeing less air, so everything was leaner than before. So at idle and low throttle angles, the PCM was having to add fuel to compensate. Well, I had to adjust the PCM fueling to put the values back like they were before I swapped MAFs.

So what did I gain? Nothing but wasted time tuning something that wasnt an issue before. Stock screened MAF is back in now. Makes idle and low speed driving a bit easier.

 

...is every so often take a look at the elements to see if they are bright and clean. If they show a build up, most commonly from a new or freshly serviced K&N, spay them with contact cleaner. Make sure the can states "Non-Residual" or "Leaves No Residue". Believe it or not there is a contact cleaner out there that leaves a "Protective Film".
There is a GM TSB stating something like this, "If a customer complains of poor shifting, gas milage, and a performance decrease, and an aftermarket oiled air filter is found, the repairs are not to be covered under warranty".
After I install a fresh K&N I will run it a week or so with several WOT runs here and there and then clean the MAF. After that I look it over every oil change. We want a good clean accurate MAF.

 

so all in all. LEAVE IT ALONE