That's a possibility with the MAF sensor and any oiled air filter. I have a K&N on my boat but run the stock filter on my Explorer. Someone who has to use the vehicle while waiting for the K&N to dry after cleaning, should keep a stock filter on hand (no dear, you can't go shopping; the filter's still wet).
If you've ever seen a video of how these are oiled at the factory you'll notice they put very little oil on them. They place a small ring of oil around the center and within an hour it wicks through the entire filter. I used this style of filter on our Ranger and oil it like that and have had no problems with the MAF with over 100,000 miles on the filter (cleaning and oiling it every 10,000 to 15,000 miles).
On the Roush I use strictly Roush filters. Its so huge that air flow and intake restriction isn't a problem and there's not much need for a higher flow filter. Just wish they didn't cost so much!
I have said this before. I use to run K&N filters in my 86 F250 4x4 460, & a 2002 Dakota 4x4 4.7L. After 25,000-30,000 miles running K&N filters I went to change spark plugs in the Dakota. 30,000 miles is recommended spark plug change interval. Well to change the plugs you have to pull the air box off on the Dakota. I was shocked at the fine dirt that was in and around the throttle body. I decided to check my Ford. Again there was a lot of fine dirt in & around the air horn. Well I decided to go back to stock paper filters after cleaning the carb & throttle body up. The next 30,000 miles on the Dakota when I changed the plugs the throttle body was clean as was the Ford carb. I have talked to several guys that run off-road and many have found the same. The only filter I have found that is a non replaceable that works real well is AirRaid Filters. I have no interest in AirRaid except they work. I have nothing against K&N except what I experienced from using them. As a former mechanic I know that the amount of dirt that K&N let through will shorten engine life. For 90% of the people that doesn't matter because most don't keep their cars & truck more than a few years then they are on a used car lot.
Crc makes the MAF cleaner(it is good preventative maint to clean it since it controls your A/f ratio) even with a stock filter there is a certain size that can't be filtered out, take a tack cloth and clean your intake out it will have dirt in it.. My ranger had a bad o ring around the pcv hose that goes into the air intake hose, on the valve cover side the o-ring had shrunk letting in dirt so I replaced the O-ring and put some dielectric to help it seal!! Just a warning simple green shrinks o-rings if you use that stuff becareful around o-ring sealed parts, That is why the military stopped using it!!
On my ranger the Iac got gunked up because the crankcase vent that comes off the passenger side valve cover had a bad o ring so it was sucking in dirt from around it and everywhere past the point it entered the intake tube was dirty.
Dont go K&N i thought it would be good quality and what not but im thinking not the oil dirtys the maf sensor which makes it run rough not worth it i put one in my truck and now it runs weird i dont think i have maf either
But still im starting to hear more bad than good from em
Not necessarily true. For instance, if you have two filters of the same size made with the same material, and one as more pleats (surface area to allow air through) it will flow more and filter better.
I tried that with filters for my home's A/C returns; based on the amount of pull required to dislodge them with the A/C running, the ones with more area (pleats) flowed less air. They don't need to be changed as often, but they sure don't flow better.