... gas tankfulls ago, so I put in my original stock filter just to see what a difference it makes. Accellerating up on-ramps, I can feel the D is choking, like it's dragging (for lack of a better word). Also after the two tankfulls, my mpg average went down from 14.3 to 13.1 using the computer readout which is 1mpg below calculated mileage.
I put the K&N back yesterday, my D is snappy again. 24000 mi ago when I replaced my stock filter with this K&N, I thought what a waste of money because I didn't notice any perf improvement then. Maybe the computer takes time to learn, or maybe it's the addition of the Borla catback and Bosch +4 plugs that requires a good flowing air intake. Maybe I need an FIPK to better improve HP.