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Exhaust Back Pressure Testing

A test on the exhaust manifold or head pipe to determine the amount of exhaust restriction.

Exhaust Emissions

Pollutants identified by clean-air legislation as being harmful or undesirable, including lead, unburned hydrocarbons, carbon monoxide, and oxides of nitrogen.

Exhaust Emissions

The exhaust that comes out of a vehicle's tailpipe or tailpipes. Harmful emissions are reduced on most newer vehicles(except diesels) through the use of a catalytic converter. Cats are designed to reduce the amount of hydrocarbons (C), carbon monoxide (CO) and oxides of nitrogen (NOx) that exit a vehicle and are therefore vented into the atmosphre. Other kinds of pollution-reduction devices have been used on cars and trucks over the years, including a positive crankcase vent valve, a charcoal canister and an air injection reactor pump.

Exhaust Gas

The burned and unburned gases that remain after combustion.

Exhaust Gas Analyzer

An instrument for determining the amount of HC , CO, CO2, O2, and NOx emitted into the atmosphere.

Exhaust Gasket

A gasket that is used between an exhaust manifold or header and the remainder of the exhaust system to prevent exhaust leakage.

Exhaust Headers

1. A term used for exhaust manifold. 2. A special exhaust manifold with tubes of equal length from the exhaust ports to the header of the exhaust system.

Exhaust Heat Control Valve

A valve which routes hot exhaust gases to the intake manifold heat riser during cold engine operation.

Exhaust Manifold

A component, generally of cast iron, with passages of unequal lengths that carry the exhaust gases from the exhaust ports tot the header of the exhaust system.

Exhaust Manifold

An exhaust system component, usually made of cast-iron, that attaches to the side of an engine's cylinder head. A V6, V8 or V10 engine will feature one exhaust manifold on each side. The exhaust manifold directs gases from each of the exhaust ports on the cylinder head into a single pipe that leads to a catalytic converter. See header.

Exhaust Note

The sound produced by an exhaust system. It can be modified most easily by changing mufflers and tailpipes. Some performance enthusiasts prefer a deeper or "throatier" exhaust note than stock. Some enthusiasts go for a louder exhaust note, while others choose to keep their vehicles quiet for a stealth approach. Motorcyclists are known for choosing a loud exhaust note for safety reasons

Exhaust Pipe

A pipe that connects the exhaust manifold, the muffler, or catalytic converter.

Exhaust Port

In a rotary combustion engine, peripheral opening in the rotor housing that allows the burned gases to leave the engine.

Exhaust Stroke

The upward motion of the piston forcing burned gases out the open exhaust valve.

Exhaust System

The tubing, mufflers, and catalytic converters that direct exhaust gases from the engine to the atmosphere.

Exhaust System

Tubing and other components that move the engine's waste products (aka exhaust gases) from the engine to the tailpipe. Most late-model vehicles feature an exhaust system with one or two exhaust manifolds, at least one catalytic converter and one or two mufflers. Race vehicles may use a "straight-through" exhaust, which does not have a catalytic converter or a muffler. See dual exhaust.

Exhaust Tip

The final part of an exhaust system, visible from the rear or side of a vehicle, depending on where the exhaust system exits. Changing exhaust tips can add some style to a vehicle or even change its exhaust note. Tips are offered in a wide variety of designs, including chrome and polished stainless steel tips in various sizes and shapes, from round and square units to a design that's shaped like a Bowtie.

Exhaust Valve

Valve that, upon opening, allows the burned gases to leave the combustion chamber during the exhaust stroke.

Exhaust Valve

A valve in a cylinder head that opens to allow exhaust gases to leave a combustion chamber. Part of a vehicle's valvetrain.

Exhaust-gas Oxygen

The amount of oxygen present in the exhaust stream, as measured by an oxygen sensor and reported to the computer in closed-loop, feedback systems to aid in the control of the air/fuel mixture.