So ya i did my 1st K&N clean and reoil a few days ago. I ntoice my car has been a complete pig and i havent caught on to the problem. I notice its been revving slower and it sounds quiet. I figured out the problem was with my filter that i reoiled. IT says to put a small amount of oil which i did, but maybe i put to little. Is it common for the engine work harder if theres not enough oil on the filter? I just put my stock paper one back and it runs so much better and sounds so much lounder. Anyone else run into this problem when re-oiling there air filter?