my experience with K&N air filter is that it actually improves mileage by about mile to a gallon.
see what i'm saying? maybe you should have re-cleaned and re-oiled the filter properly, instead of getting mad at it and removing it?

 

It was just cleaned and oiled not even a month ago I don't get mad at air filters LOL. I removed it to see if the new old style filter helped anything. which it seems to have gotten a bit better I haven't pulled the big trailer I usualy pull yet to know for sure, tomorrow should tell the tale as to weather the MAF cleaning and the new filter made a difference.