Before you begin
The air filter plays an important role in your engine by keeping dirt, dust, and other debris out of the combustion chamber. Because of that, the air filter needs replaced every 10,000 to 15,000 miles, depending on the driving conditions. NOTE: This guide uses a 4.6L V8 engine on a 2003 Ford F-150 to demonstrate the procedure. Before beginning this guide, make sure that your truck is off and in park with the emergency brake on.