what brand? Should be able to wash it out and reoil the finlter if it is a K&N. they make a cleaning kit for them.
Stock, just tap the filter on the ground fins down all around and that should make some dirt fall out if there is any.
A forum community dedicated to Ford Mustang owners and enthusiasts. Come join the discussion about performance, builds, modifications, reviews, engine swaps, classifieds, troubleshooting, maintenance, and more!