Question A broken exhaust system: Answers Can allow poisonous fumes to enter the cabin. Does not cause problems. Should not be a concern. Explanation A broken exhaust system can let poisonous fumes into a vehicle's cab or sleeper berth. Be sure to inspect your exhaust system for any loose, broken, or missing parts. Take a FREE Practice Test Now This questions appears in the following tests: Washington Knowledge Test Class A , Missouri Knowledge Test Class B ,