2026 Class B Passenger Endorsement Practice Test – Comprehensive Exam Prep

In winter driving, the exhaust system needs extra attention because a leak can allow deadly carbon monoxide to enter the cab, especially when the heater or defroster is being used and the vehicle interior is sealed up for warmth. A small crack or loose connection can become more dangerous in cold weather as components contract and expand, and snow or ice can block the tailpipe, causing CO to back up into the vehicle.

So, check for signs of leaks, rust, holes, or loose clamps, ensure hangers are secure, and make sure the tailpipe is free of snow or ice. This focus helps prevent CO buildup and keeps the vehicle safer to operate in winter conditions.