Control of Air Pollution From Motor Vehicles and New Motor Vehicle Engines; Modification of Federal On-board Diagnostic Regulations for Light-Duty Vehicles and Light-Duty Trucks; Extension of Acceptance of California OBD II Requirements

Today's action finalizes modifications to the federal on-board diagnostics regulations, including: harmonizing the emission levels above which a component or system is considered malfunctioning (i.e., the malfunction thresholds) with those of the California Air Resources Board (CARB) OBD II requirements; mandating that EPA OBD systems fully evaluate the entire emission control system, including the evaporative emission control system; indefinitely extending the allowance of deficiencies for federal OBD vehicles; indefinitely extending the allowance of optional compliance with the California OBD II requirements for federal OBD certification while also updating the allowed version of those California OBD II regulations to the most recently published version; providing flexibility to alternate fueled vehicles through the 2004 model year rather than providing flexibility only through the 1998 model year; updating the incorporation by reference of several recommended practices developed by the Society of Automotive Engineers (SAE) to incorporate recently published versions, while also incorporating by reference standardization protocol developed by the International Organization for Standardization (ISO). OBD systems in general provide substantial ozone benefits.