Aftermarket exhaust parts and the engine. However, the pipes do "ring" with the exhaust pulses and increase underhood noise. Headers can be ceramic coated to reduce the heat radiated in the engine compartment, and to increase the temperature of the pipes which increases the velocity of the exhaust gases. Terminology: Catalytic converters are necessary to reduce emissions but create back pressure due to the exhaust gases being forced through a catalyst, and therefore decrease high-end engine power. Many modern catalytic converters only produce 1-3 psi of back pressure, though this restriction worsens further with use. Hi-flow catalytic converters can replace the standard units
Emily Vanhoutte this because exhaust gases are the main sources of air pollution. Actually, many people are exposed to exhaust emissions every day in different ways: motor vehicles running on fuel and diesel, trains, ships, electric generators, factories and plants. When you take the bike and leave your car at home you reduce the air pollution and save our planet. 4. I did a campaign to promote windmills. A windmill is a machine that converts the energy of wind. Green energy is important to save the health of our planet. Clean electricity generated from the wind is important for our future but