The K&N 33-2221 is a reusable, panel-style replacement engine air filter for the 1.6-liter 16-valve four-cylinder in the VW Golf and Bora. Its layered, oiled cotton gauze media is built to keep airflow high while catching dirt, and the manufacturer rates it at up to 99% filtration efficiency. It is designed to drop into the factory airbox, so no housing modifications are needed.
A paper stock element gets thrown away at every service, while this one can be cleaned and re-oiled. The manufacturer says it can be serviced with a K&N Recharger kit as often as necessary, and it carries the company's No-Hassle Lifetime Limited Warranty. Service timing depends heavily on conditions: the manufacturer cites up to 50,000 miles of normal highway driving, but far less in dusty or racing use. Enthusiasts on user forums stress that the element must be completely dry before oiling. For VW Golf IV and Bora owners searching for a 1.6 16V cotton gauze drop-in air filter, a reusable K&N element is a lasting upgrade over a disposable one. Listings disagree on the model-year range, so confirm your year and engine code before ordering.
Yes. The manufacturer states that K&N High-Flow filters can be cleaned and re-oiled with a K&N Recharger kit as often as reasonably necessary. Follow the oiling directions in the kit closely.
The manufacturer says the service interval varies widely with driving conditions, from as little as 100 miles in desert racing to up to 50,000 miles under normal highway driving.
This is a drop-in swap, not a modification. K&N's install sheets for similar drop-in elements describe removing the airbox lid or clips, lifting out the stock filter, seating the K&N element, and reassembling so the airbox seals. Wipe out the airbox before reinstalling so debris does not bypass the filter. The manufacturer stresses that these steps must be repeated every time the filter is serviced, because an unsealed filter can allow unfiltered air into the engine. The install sheet for this exact part number was not retrieved, and the sheets reviewed did not list required tools, so confirm the procedure with the manufacturer before starting.
