The OEM intake tube is small in diameter and highly restrictive. S&B's intake tube was designed with a huge diameter to allow for insane amounts of airflow to be fed to your engine. More airflow equals better performance. We use an innovative insert in order to get our gigantic tube to work with the MAF sensor parameters of a stock truck.
Important Note: Removing this insert will cause your truck to drive poorly and possibly display a check engine light, as it will no longer conform to the stock calibration’s desired MAF readings.