The U.S. Environmental Protection Agency recently approved changes to the vehicle inspection and maintenance program of the State of Illinois. These changes were proposed by the Illinois EPA as revisions to the State Implementation Plan, which details how Illinois will comply with the Clean Air Act and its implementing regulations.

The major changes to the emission testing program either eliminate certain tests or exempt certain vehicle models from testing:

• The elimination of the IM240 transient mode exhaust test for all vehicles beginning February 1, 2007.
• The elimination of the evaporative system integrity (gas cap pressure) test for all on-board diagnostics (OBD) compliant vehicles beginning February 1, 2007.
• The replacement of the computer-matching enforcement mechanism with a registration denial based system beginning January 1, 2008.
• The elimination of the steady-state idle exhaust and evaporative integrity (gas cap pressure) testing for all vehicles beginning February 1, 2012.
• The exemption of pre-2007 model year (MY) heavy-duty vehicles (HDVs) with gross vehicle weight rating (GVWR) between 8,501 and 14,000 pounds beginning February 1, 2012.
• The exemption of all HDVs with a GVWR greater than 14,000 pounds as of February 1, 2012.
• The requirement of OBD pass/fail testing for all 2007 and newer OBD-compliant HDVs.

To demonstrate to U.S. EPA that these revisions would not increase air emissions, the State identified over 1,000 facilities with permitted volatile organic compound (VOC) emissions and over 700 facilities with permitted nitrogen oxide (NOx) emissions that have permanently closed and have expired permits that have been revoked.