Problem with the K & N is that you cut the factory vent tube that connects to the K&N. So going back to stock means you need to go to a scrap yard and pull another tube. I find a bit of bogging at lower rpms. I'm seriously considering pulling it off, selling it and using the money for a tuner. Most of the power gains that they advertise are at high RPM's where, unless you own a gas station, you rarely are driving a HEMI powered Ram.