sheipe05

I appreciate all the input guys! I didn't mean to start any arguments though The intake air temp should not have changed since I did not install the complete "cold air intake system" Kinda ironic being called the "cold" air intake system. I have put K&N air filters in every vehicle(and Quad) I've ever had and had some kind of increase in mpg and a little increase in hp especially climbing hills. For example, I had a Ford Ranger that got 20 mpg on my (mostly highway)trip to work every week. After the filter on the same trip I got just shy of 23 mpg. I guess it depends on the vehicle. I will try and reset the ECU as suggested. I will keep you updated. Thanks again!! Kevin

Yes, I replaced all of those not too long ago. I installed the filter straight from the box. I did not add any oil since it was pre=oiled from factory.

I have a 2001 Legacy. I installed a K&N air filter and it seems like I am getting worse gas mileage. I'm only getting around 21 miles per gallon mixed city and highway. Has anyone else had this problem? Thank You!! Kevin

it sounds more like a knock than a lifter tap.

I just bought an '01 Legacy a few months ago. I noticed a slight knocking sound especially when the engine is cold. I read a little about people having "piston slap" and replaced the pistons. Others say it's normal and the noise goes away when the engine warms up as the pistons expand. I didn't think much of it until my check engine light came on. it gives me a knock sensor error. Has anyone heard anything on this issue?