Exhaust

Emissions Controls

Automobiles release far fewer pollutants into the atmosphere than they did 20 years ago, thanks to sophisticated emission control systems. There are two critical elements to these systems which, over time, commonly need replacement.

Catalytic converter. This device converts dangerous polluting gases (such as carbon monoxide) into water vapor and less harmful gases. When a replacement converter is needed, it is often smaller than the original, factory-installed equipment, thanks to continually improving technology which lets converters work more efficiently.

Oxygen sensor. This device constantly monitors the percentage of oxygen present in exhaust gases and transmits that information to the engine control computer. The computer then adjusts the air/fuel mixture to assure the cleanest combustion. A properly functioning oxygen sensor is therefore critical to engine performance.

Exhaust System

Troubleshooting Process

Exhaust manifolds and gaskets: check for cracks that may cause leaks.

Mufflers and resonators: look for rusty, jagged holes, especially around seams at the front and back. Also check for rust on connections. Listen for rattles indicating loose internal parts.

Vacuum components in the emission control system: check valves, delay valves, diaphragms, hoses and tubes.

Oxygen (O2) sensor: check for damaged signal wires, blocked air intake openings, cracked sensor body or oil contamination.

Catalytic converter: examine for discoloration (a sign of overheating) as well as external dents, clogging or corrosion. Listen for rattles indicating loose internal parts.