{"data":{"id":"us-va/9vac5-91-180","jurisdiction":"us-va","citation":"9VAC5-91-180","heading":"On-road high emitter emissions standards for on-road testing through remote sensing","body":"A. No affected motor vehicle shall exceed the on-road high emitter emissions standards for carbon monoxide (CO), hydrocarbons (HC), or nitric oxide (NO) when measured with a remote sensing device and in accordance with the inspection procedures prescribed in Part XII (9VAC5-91-740 et seq.).\n\nB. The on-road high emitter emissions standards for a vehicle shall be determined by multiplying the value in the Table III-B of 9VAC5-91-180 by the ASM 25-25 standard in 9VAC5-91-810 or two speed idle standard in Table III-A of 9VAC5-91-160 as is applicable for the vehicle.\n\nC. Any affected motor vehicle determined to have exceeded any on-road high emitter emissions standards when measured by a remote sensing device in accordance with the procedures of Part XII (9VAC5-91-740 et seq.) may be subject to an emissions inspection at an emissions inspection station in accordance with Part XII (9VAC5-91-740 et seq.) or a civil charge in accordance with § 46.2-1178.1 B of the Code of Virginia, or both.\n\nD. Any affected motor vehicle that exceeds the on-road high emitter emissions standards two days in any 120-day period shall be considered to have violated the emissions standards. In addition, the department may use the vehicle emissions index as a screening requirement.\n\nE. Any affected motor vehicle that exceeds the on-road high emitter emissions standards once and is also determined to have a vehicle emissions index of greater than 75 shall be considered to have violated the on-road high emitter emissions standards.\n\nF. All remote sensing measurements used to determine if a vehicle exceeds the on-road high emitter emissions standards shall be taken at valid sites under conditions at which the vehicle specific power (VSP) indicator is between 3 and 22. Standards for NO shall be corrected for VSP using the following formula:\n\nNO standard = Low Range Value + (VSP-3)/\n\n19 x (High Range Value - Low Range Value).\n\nWhere:\n\nLow Range Value = the smaller values in Table III-B in the NO (ppm) Range column;\n\nVSP = vehicle specific power indicator; and\n\nHigh Range Value = the larger values in Table III-B in the NO (ppm) Range column.\n\nG. The director may adjust the values in Table III-B if it is determined that an on-road high emitter emissions standard is causing a confirmation test pass rate in excess of 20% or less than 5.0%. Such adjustments may be for specific models within each model year group based on manufacturer's emissions control technology.\n\nTABLE III‑B.\n\nHIGH EMITTER VALUES FOR REMOTE SENSING\n\nOne or More On-Road Measurements\n\nASM Based\n\nVehicle Must Have a Vehicle Emissions Index of 75% or Higher\n\nPeriod/Model Year/Vehicle Type\n\nCO\n\nHC\n\nNO Range(1)\n\nLow\n\nHigh\n\n1981 through 1990 - LDGT (1 or 2)\n\n4.0\n\n5.0\n\n2.5\n\n3.3\n\n1981 through 1990 - LDGV\n\n12.0\n\n4.5\n\n1.5\n\n2.0\n\n1991 through 1995 - LDGT (1 or 2)\n\n4.0\n\n5.0\n\n2.5\n\n3.3\n\n1991 through 1995 - LDGV\n\n8.0\n\n6.0\n\n1.5\n\n2.0\n\n1996 and newer - LDGT (1 or 2)\n\n7.0\n\n4.5\n\n2.5\n\n3.3\n\n1996 and newer - LDGV\n\n9.0\n\n6.0\n\n2.2\n\n2.9\n\nTwo or More On-Road Measurements\n\nASM Based\n\nPeriod/Model Year/Vehicle Type\n\nCO\n\nHC\n\nNO Range(1)\n\nLow\n\nHigh\n\n1981 through 1990 – LDGT (1 or 2)\n\n3.0\n\n3.8\n\n2.1\n\n2.8\n\n1981 through 1990 – LDGV\n\n9.0\n\n3.4\n\n1.3\n\n1.7\n\n1991 through 1995 – LDGT (1 or 2)\n\n3.0\n\n3.8\n\n2.1\n\n2.8\n\n1991 through 1995 – LDGV\n\n6.0\n\n4.5\n\n1.3\n\n3.3\n\n1996 and newer LDGT (1 or 2)\n\n5.3\n\n3.4\n\n2.1\n\n2.8\n\n1996 and newer LDGV\n\n6.8\n\n4.5\n\n1.9\n\n2.5\n\nOne or More On-Road Measurements\n\nTSI Based\n\nVehicle Must Have a Vehicle Emissions Index of 75% or Higher\n\nPeriod/Model Year/Vehicle Type\n\nCO\n\nHC\n\nNO Range(1)\n\nLow\n\nHigh\n\n1968 through 1980– LDGT (1 or 2)\n\n2.0\n\n1.5\n\n1968 through 1980 – LDGV\n\n2.0\n\n1.5\n\n1968 through 1980 – HDGV\n\n2.0\n\n1.5\n\n1981 through 1990 – LDGT (1 or 2)\n\n3.0\n\n3.5\n\n1981 through 1990 – LDGV\n\n3.0\n\n3.5\n\n1981 through 1990 – HDGV\n\n3.0\n\n3.5\n\n1991 through 1995 – LDGT (1 or 2)\n\n3.0\n\n4.0\n\n1991 through 1995 – LDGV\n\n3.0\n\n4.0\n\n1991 through 1995 – HDGV\n\n3.0\n\n4.0\n\n1996 and newer – LDGT (1 or 2)\n\n4.0\n\n4.0\n\n1996 and newer – LDGV\n\n4.0\n\n4.0\n\n1996 and newer – HDGV\n\n4.0\n\n4.0\n\nTwo or More On-Road Measurements\n\nTSI Based\n\nPeriod/Model Year/Vehicle Type\n\nCO\n\nHC\n\nNO Range(1)\n\nLow\n\nHigh\n\n1968 through 1980– LDGT (1 or 2)\n\n1.5\n\n1.1\n\n1968 through 1980 – LDGV\n\n1.5\n\n1.1\n\n1968 through 1980 – HDGV\n\n1.5\n\n1.1\n\n1981 through 1990 – LDGT (1 or 2)\n\n2.3\n\n2.6\n\n1981 through 1990 – LDGV\n\n2.3\n\n2.6\n\n1981 through 1990 – HDGV\n\n2.3\n\n2.6\n\n1991 through 1995 – LDGT (1 or 2)\n\n2.3\n\n3.0\n\n1991 through 1995 – LDGV\n\n2.3\n\n3.0\n\n1991 through 1995 – HDGV\n\n2.3\n\n3.0\n\n1996 and newer – LDGT (1 or 2)\n\n3.0\n\n3.0\n\n1996 and newer – LDGV\n\n3.0\n\n3.0\n\n1996 and newer – HDGV\n\n3.0\n\n3.0\n\n1NO Value = Low Range Value + (Actual VSP-3)/19 x   (High Range Value – Low Range Value)","path":["Title 9. Environment","Agency 5. State Air Pollution Control Board","Chapter 91. Regulations for the Control of Motor Vehicle Emissions in the Northern Virginia Area"],"source_url":"https://law.lis.virginia.gov/admincode/title9/agency5/chapter91/section180/","current_through":"2026 Regular Session (effective July 1, 2026)","vintage":"","retrieved_at":"2026-09-14T04:48:41Z","sha256":"2047d7f1b1738201c247b3dff7db58adda73ff7fe96f85c887dd05401c805743","source_id":"us-va-vac","stale":false,"prev":"us-va/9vac5-91-170","next":"us-va/9vac5-91-185"},"notice":"GroundRules: Original legal text. Not legal advice."}