After installing a k&n intake whenever I decelerate between 30-50 mph my cars rpm shake a little. The car gets a little jerky. Is my car running lean? Should I just put the old intake on? If I disconect my battery and reset my computer will that help? Everything is nice and tight no air leaks. Would running premium help? I have no idea. K&N says its not their intake when I emailed them but I think their full of crap. Because it never did this before I installed it and the car only has 40000 miles on it so it shouldn't have problems.