BMW 18407556990 Exchange. Exhaust Manifold With Catalyst

A well-maintained and well-driven catalytic converter should last between 50,000 and 100,000 miles. If the converter is no longer effective, it must be replaced. It's important to note that the catalytic converter is integral with the exhaust manifold, and they are replaced as a unit.

For a 3.0L engine: Remove the fuel injectors and air filter housing. Disconnect the wiring plugs from the throttle body/manifold. Release the wiring harness/cables from the retaining clips/bolts. Disconnect the breather hose from the manifold. Remove the manifold retaining bolts. Lift the manifold and disconnect the hose on the base of the tank venting valve. Disconnect any hoses or wiring harnesses from the retaining clips on the manifold and support bracket. Remove the manifold from the cylinder head and check the condition of the seals. Replace them if necessary.