Horse Sense:Because we're presenting MagnaFlow's new X-pipe so early in its product cycle, it doesn't yet carry a CARB E.O. number, but it will. MagnaFlow's own catalytic converters have easily passed ...

But even by naturally aspirated standards, this Mustang's exhaust seemed woefully inadequate. A leftover from its milder days, the '79 exhaled through 1 5/8-inch shorty headers, a 2 1/2-inch off-road ...

Don't try to make a list of all the aftermarket exhaust goodies currently available for the S550 Ford Mustang in the US, unless you have quite a lot of time to invest in this aftermarket adventure.