# COMAR Title 11 — Department of Transportation

## Subtitle 14 — Motor Vehicle Administration — Vehicle Inspections

### Chapter 06 — Emissions Equipment Standards

#### Regulation .06 Exhaust Gas Recirculation System (EGR).

*COMAR 11.14.06.06*

A. Most 1973 and later model vehicles are equipped with an exhaust gas recirculation system to recirculate proper amounts of exhaust gases into the air/fuel mixture in the intake manifold. This recirculation into the manifold reduces combustion temperatures, thus reducing oxides of nitrogen (NOx).  There are several types of EGR systems: a back pressure system which operates in conjunction with exhaust back pressure, a conventional system which operates on carburetor venturi vacuum, an electronically controlled system which operates from the engine computerized emissions control system, or a floor jet system which operates through jets in the floor of the intake manifold.