An oversized exhaust used to compensate for have a weedwacker engine under the hood (see honda). Its sole purpose is to reduce performance and generally annoy anyone within a quarter mile radius. Popular among 16 year old white boys who think they're black.
This also leads to the expression: The bigger the exhaust, the smaller the penis.
That little wigger across the street put a fart pipe on his crappy Civic. It woke me up at 5am, so I called the cops.