Answer: You should have your entire exhaust system inspected every two to three years, depending on driving conditions. If the manifold appears to be worn or damaged in any way, it should be replaced to ensure safe driving conditions. However, it is recommended that you periodically inspect your vehicle’s exhaust system to check for any damage or leaks. Also, if you are able to smell your engine’s emissions, you may have a leak somewhere and should have your entire exhaust system checked. Another sign of a faulty exhaust system can be when your “check engine” light comes on and stays on. If you observe any of these issues, have your exhaust system inspected. If a problem is found with your manifold, you should have it replaced