Review on K&N Engine Air Filter: Premium Performance Replacement (Land Cruiser, Tundra, Sequoia, LX 570) by Johnnie Trimble

Pros: Great filter with excellent airflow to the engine. Lasts longer than a car with regular cleaning and oil spraying so saves you money in the long run. Disadvantages: This is not a disadvantage for this filter. Negative for Toyota: Fitting this filter reveals a fault in the Toyota 5.7 liter engine where the very high pitched sound is produced by the metal mesh behind the throttle body. The OEM filter masks this noise (probably due to its density and airflow limitation). To fix this, remove the two bolts holding the throttle body to the intake manifold (having first removed the air cleaner housing) and then use wire cutters to snip the wire braid from the gasket behind the throttle body. Replace and the high frequency noise will go away. (I installed a new stereo around the same time as this filter and thought the noise was coming from the radio. Very high pitched and sounds like it was coming from the saloon speakers. Enough to drive anyone crazy looking for it).