Air Filter

I like KNN filters on cars that we race but for street cars I don't know if there is value/performance gain. I inspect and blow out my own air filters when I change my oil and replace them when they are dirty or every 15 to 18000 miles. Modern cars are very sensitive. There was a rash of air flow meter problems with several makes of cars. The car manufactures tried to pin blame on aftermarket air filters an in particular the KNN air filter replacements. Lots of talk on several car club websites. It depends on who's propaganda you want to believe. I'd say stick with the stock filter inspect/blow it out periodically, replace when dirty and remove debris from air filter housing as required.