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The K&N drop‑in high‑flow air filter for BMW M3 L4 2.3L (1986–1991) replaces the stock element to increase airflow and potential horsepower while providing engine protection. K&N's layered, oiled cotton media is washable and reusable, designed to trap contaminants without sacrificing flow. The filter installs into the factory airbox and is backed by K&N's No‑Hassle Lifetime Limited Warranty.
K&N Replacement Air Filter BMW F/I CARS 1978-91
