Using your Tomioka equal length exhaust manifold is straightforward. First, make sure your Subaru WRX is turned off and cooled down. Remove the old exhaust manifold carefully following your vehicle's repair manual. Then, install the new exhaust manifold from the kit, using the provided gaskets and hardware. Tighten all the bolts properly but don't over - tighten. When it comes to maintenance, regularly check the gaskets for any signs of wear or leaks. If you notice any issues, replace the gaskets promptly. Keep the stainless - steel manifold clean by washing it with mild soap and water, and dry it thoroughly to prevent rust. Avoid using abrasive cleaners that could scratch the finish. And always remember to have your vehicle serviced regularly to ensure the exhaust system works at its best.