Recently I decided to put a K&N Air Filter on my 2007 Land Rover Range Rover L322. I had a mass airflow sensor go bad, so while doing that work, I replaced the air filter. All was fine, but after a few thousand miles, I started to notice weird RPM swings. I decided to do a Seafoam Top Engine treatment and on that video, a subscribed mentioned that sometimes with K&N Air Filters the oil can cause issues with the airflow reading on the MAF sensor. I heard this before, but it dawned on me when he posted. Perhaps that is why I am having these issues? They aren’t frequent, but enough to notice.
This is my story using a K&N Air Filter on my 2007 Land Rover Range Rover L322 and I am now back to using a standard paper filter. So far, the paper filter has resulted in no odd RPM swings when coming to a stop. I plan to put another 500 or so miles on it, before I really consider the K&N air filter being the issue. What I can tell you, this bad boy was dirty and seemed to have even more oil on it than when I first installed it.