Straight-through, or flow-through, mufflers have perforated baffles and packing material that provides a conservative level of sound absorption while still keeping sound output moderately loud. Glasspack mufflers perform similar to resonators due to their design and lack of sound-absorbing packing material, so they tend to be louder and higher pitched. For compression-ignition (i.e., diesel) engines, the most commonly used catalytic converter is the diesel oxidation catalyst (DOC). This catalyst converts particulate matter (PM), hydrocarbons, and carbon monoxide to carbon dioxide and water. These converters often operate at 90 percent efficiency, virtually eliminating diesel odor and helping reduce visible particulates. These catalysts are ineffective for NOx, so NOx emissions from diesel engines are controlled by exhaust gas recirculation (EGR).

Unwanted reactions result in the formation of hydrogen sulfide and ammonia, which poison catalysts. Nickel or manganese is sometimes added to the washcoat to limit hydrogen-sulfide emissions.[citation needed] Sulfur-free or low-sulfur fuels eliminate or minimize problems with hydrogen sulfide. It also boasts the ultimate in customization, including the optional 700+ horsepower Shelby GT S/C version.

Invidia offers products known for their outstanding quality, and each finished piece is a work of art that sets them apart from the competition. For anyone looking to take their vehicle to the next level, Invidia is a name to remember. So, a cat back is used to indicate an upgrade to the stock exhaust system. And anyone looking to improve their ride should strongly consider a cat back exhaust system. This pipe will connect your mk1 downpipe that we sell for&nbsp