Here's a breakdown of how to approach the problem:
1. Identify the Leak:
* Listen: Start the engine and listen carefully. Walk around the car to pinpoint the location of the hissing or rumbling sound.
* Inspect Visually: Once you've got a general area, carefully inspect the exhaust system. Look for cracks, holes, loose clamps, or broken hangers. Use a flashlight to get a good look in hard-to-reach areas. Be careful – the exhaust system is hot when the engine is running.
* Smoke Test (Optional but Helpful): If you can't easily locate the leak, you can use a smoke test. This involves introducing smoke into the exhaust system (using a specialized tool or even carefully plugging a hole and using a shop vac in reverse). The smoke will escape through the leak, revealing its location.
2. Determine the Repair Method:
The best repair method depends on the location and severity of the leak:
* Loose Clamps: This is the easiest fix. Simply tighten the clamp(s) using a wrench. Make sure the gasket (if present) is properly seated.
* Small Holes or Cracks (in pipes or muffler): For small holes or cracks in accessible areas, you can try a temporary repair with exhaust sealant or a high-temperature patching compound. These are available at most auto parts stores. This is a temporary solution; eventually, the damaged section will need to be replaced.
* Larger Holes or Cracks, or Rotted Sections: Larger holes, significant cracks, or sections of rusted-out pipe will require replacing the damaged section of the exhaust system. This usually involves cutting out the bad section and welding in a new piece (requires welding skills or a professional welder). Alternatively, you may be able to use exhaust clamps and sections of pipe to create a temporary repair. However, this is not ideal for long-term use.
* Broken or Rotted Muffler or Catalytic Converter: These will likely need to be replaced. These parts are often expensive, and some states have regulations regarding catalytic converter replacement (they may need to be original equipment or have specific certifications).
* Exhaust Manifold Leak: Leaks in the exhaust manifold are more complex to repair and often require professional attention. They can sometimes be fixed with manifold gaskets, but often require welding or replacing the entire manifold.
3. Tools and Materials (Depending on the Repair):
* Wrenches (various sizes)
* Jack and jack stands (for safe working conditions)
* Exhaust sealant or patching compound
* Exhaust clamps
* Replacement exhaust pipe sections (if needed)
* Welding equipment (if needed)
* Gloves and safety glasses
* New gaskets (if needed)
4. Safety Precautions:
* Let the Exhaust Cool Completely: Before working on the exhaust system, let the car cool down completely. The exhaust system gets extremely hot during operation.
* Work in a Well-Ventilated Area: Exhaust fumes are toxic. Work in an open space or use a respirator if working in a confined area.
* Use Jack Stands: Never work under a car supported only by a jack. Always use jack stands for safety.
* Wear Protective Gear: Always wear gloves and safety glasses.
When to Seek Professional Help:
If you are not comfortable with automotive repair or the leak is in a difficult-to-reach area, it's best to take your Mustang to a qualified mechanic. Exhaust system repairs can be tricky, and a poorly done repair can lead to further problems (like carbon monoxide poisoning). Replacing the catalytic converter or exhaust manifold is almost always best left to professionals.
