A high-quality Subaru EGR valve can have a positive impact on your car's overall performance. The EGR valve needs a reliable Subaru EGR valve gasket to help it send a controlled amount of exhaust gas back to the engine's cylinders. A faulty gasket allows too much gas into the engine's cylinders, causing excessive backpressure. So, to keep your car's exhaust emissions under control, make sure that your car is equipped with a functional EGR valve gasket.