Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines; Modification of Federal On-Board Diagnostic Regulations for: Light-Duty Vehicles, Light-Duty Trucks, Medium Duty Passenger Vehicles, Complete Heavy Duty Vehicles and Engines Intended for Use in Heavy Duty Vehicles Weighing 14,000 Pounds GVWR or Less

EPA is finalizing certain requirements associated with the Federal on-board diagnostic (OBD) system regulations. On June 17, 2003, EPA published both a direct final rule and a concurrent notice of proposed rulemaking (68 FR 35972 and 68 FR 35830 respectively) to amend and revise certain provisions of the Federal OBD regulations. EPA published the direct final rule believing that no adverse comments would be received. However, due to the receipt of an adverse comment, EPA published a partial withdrawal notice on August 14, 2003 (68 FR 48561) withdrawing two specific regulatory amendments included in the direct final rule. The direct final rule, absent those two withdrawn provisions, became effective on August 18, 2003. The purpose of this action is to finalize the portion of the direct final rule that was withdrawn with the revisions suggested by the commenters and to clarify several smaller issues that were raised by industry during the comment period.