What does the A and B mean on a muffler?

The letters A and B on a muffler typically represent different flow paths or configurations within the muffler system. In dual exhaust systems, "A" may refer to one side of the system, while "B" refers to another, indicating how exhaust gases are directed or how noise is managed. These designations can also indicate different levels of sound attenuation or performance characteristics, depending on the manufacturer's design. Always refer to the specific muffler's documentation for precise meanings.