After how many miles should i take the filter off and wash it??

 

This is what it says on the side of the Recharger Filter Care Service Kit #99-5050:

"Service every 50-100,000 miles on street driven applications. Service more often in off-road or heavy dust conditions or when air filter reaches 18" of restriction. Let the dirt "build-up" work for you; it will not hurt the performance and actually help filter the air."

 

I usually clean mine when I change the fuel filter and pcv valve. Around 15K.