1. When the engine is cold (at least one hour after driving) check the entire exhaust system, from the engine to the cut of the exhaust pipe. Raise the vehicle with a hoist or jack it up and securely jack it up to make it easier to check (see «Lifting and placing the car on supports»). Then the elements of the exhaust system will be visible and accessible.
2. Check the exhaust pipes and their connections for signs of leakage, severe corrosion or damage. Ensure that all brackets and supports are in good condition and that all relevant nuts and bolts are securely tightened. Leaks at any of the connections or other parts of the system usually show up as black soot in the immediate vicinity of the leak.
3. The exhaust system, especially brackets and supports, is often a source of rattling and other noises. Try to shake pipes and mufflers. If the elements may come into contact with the body or suspension elements, secure the system with new supports. Otherwise, disconnect the connections (if it is possible) and rotate the pipes to provide additional clearance.