Random Technology catalytic converters actually have a higher flow capacity than most mufflers. As an example, a 3" diameter Super High Flow converter flows 501 cfm. Most 3" diameter high performance mufflers flow less than 475 cfm at the same test pressure. Random Technology direct fit Super High Flow catalytic converters are now available for most domestic and imported vehicles. Custom catalytic converters with inlets and outlets up to 4" in diameter are available.