United States Air and Radiation EPA420-F-98-002 Environmental Protection January 1998 Agency Office of Mobile Sources &EPA Regulatory Announcement Proposed Amendment to On-Board Diagnostic Checks Requirement for I/M Programs The U.S. Environmental Protection Agency (EPA) is proposing to extend, by a period of three years, the deadline by which states must implement On-Board Diagnostic (OBD) checks as a regular part of their I/M programs. Prior to this proposed new deadline of January 1, 2001, states may opt to include OBD checks and fail vehicles based on OBD failure alone. States may not earn emission reduction credit, however, unless exhaust and evaporative tests are performed as well. Should EPA and states complete testing and review of OBD systems sooner than expected, the Agency may be able to make credits available to states who choose to implement OBD I/M checks prior to the proposed deadline. Background On August 6, 1996, EPA published a final rulemaking relating to the implementation of OBD checks as a routine part of I/M programs. In the rule, EPA interpreted the Clean Air Act requirement to include both emission testing and OBD checks and thus required both tests as part of the regular I/M test procedures. Ozone Transport Region (OTR) areas with OTR low enhanced programs were to implement OBD checks by January 1, 1999, and all other areas were to implement OBD checks by January 1, 1998. Until January 1, 2000, OBD checks, exhaust tests and evaporative system tests, where applicable, were to be required on each subject vehicle of model year 1996 and newer. After January 1, 2000, failure of the OBD test would require mandatory repair. I Printed on Recycled Paper ------- Overview of Proposed Rule This rule proposes to delay the required implementation date for OBD by setting the new implementation deadline as January 1, 2001, for all areas with basic and enhanced I/M programs. This amounts to a two year delay for OTR low enhanced areas and a three year delay for all others. During this time extension, EPA will work with states and other stakeholders to generate, collect and analyze the data necessary to determine the effec- tiveness of OBD systems in an I/M setting. EPA is currently conducting such a study which began October 1, 1997. Two years are needed to ensure ample time for fleet penetration of OBD- equipped vehicles, so that enough vehicles can be recruited for the study. A third year will be needed to allow sufficient time to analyze the data generated by the study. In addition, EPA is proposing certain clarifying amendments to allow for updates to the Code of Federal Regulations which are cross-referenced in the OBD rule. Section 86.094-17, which includes the technical specifica- tions for OBD systems, is periodically updated to include new require- ments. This rule proposes to amend the sections of the OBD rule where that subsection is referenced with new language which obviates the need for future amendments in this regard. This proposed rule does not affect the requirement that states revise their I/M State Implementation Plans by August 6, 1998, to include the OBD checks. Also unchanged are the sections which allow states the option to implement OBD inspections before December 31, 1999, and to allow failure of OBD to result in failure of the I/M test, thereby requiring repair. However, states which choose to conduct OBD checks cannot earn emission reduction credits for doing so unless they also perform the exhaust and evaporative tests, where applicable, or unless EPA completes its analysis and determines appropriate credit sooner than expected. Effect of Proposed Rule This proposed rule will allow the states even greater flexibility in design- ing and implementing I/M programs which meet their local needs and help them to move towards attainment. In addition, it will reduce the cost burden the states would face if they were required to run OBD checks concurrently with the exhaust and evaporative tests as required by the previous rule, so this amendment will produce a net savings. The I/M ------- testing requirements will now be less burdensome in terms of test time, equipment and cost. Furthermore, it is not certain that the requirement would have generated additional emission reductions to justify the added cost. OBD equipment suppliers and I/M contractors may need to adjust to shifting requirements resulting from this proposed rule. Automobile manufacturers will see a delay in the generation of some data on OBD in-use performance. The general public will not be affected by the proposed delay, as it only postpones a requirement to which most have not yet been subjected. The proposed delay will have no appreciable effect upon the environ- ment. The vehicles which would otherwise be subject to the OBD check will still receive exhaust and evaporative (where applicable) testing, if the state is earning emission reduction credits for those vehicles. Emis- sion reductions will still be achieved for those vehicles despite the delay in OBD checks. For More Information Additional documents on I/M programs and OBD are available elec- tronically from the EPA Internet server at: http://www.epa.gov/OMSWWW/im.htm Document information is also available by contacting Russ Banush at: U.S. Environmental Protection Agency Office of Mobile Sources 2565 Plymouth Road Ann Arbor, Michigan 48105 (734) 668-4333 ------- |