What is the reason for black soot on the exhaust pipe when touched by hand?

[LaAmelia]

The reasons for black soot on the exhaust pipe when touched by hand are: 1. The vehicle is burning engine oil; 2. Incomplete combustion of gasoline; 3. The engine frequently operates at low speeds, resulting in low air intake volume and capacity, preventing proper mixing of gasoline and air. Solutions for black soot on the exhaust pipe when touched by hand include: 1. Remove the intake pipe to clean carbon deposits from the throttle body; 2. Avoid frequent braking. The exhaust pipe is part of the engine's exhaust system, which includes the front exhaust pipe and rear exhaust pipe. The exhaust system mainly consists of the exhaust manifold, exhaust pipe, and muffler. The three-way catalytic converter, which controls engine pollutant emissions, is also installed in the exhaust system.