Black smoke, a hanging exhaust, or a leaking fuel tank appears on your C vehicle. What should you do?

1. Continue; exhaust and fuel leaks are only an environmental issue, not a safety issue
2. Rev the engine in a tunnel to burn the smoke away
3. Do not drive until the exhaust, fuel and environmental defects are made safe; they are both pollution and fire or fume hazards
4. Remove the exhaust silencer to reduce back-pressure