OVI Testing
The right test for 2012 and older diesel rigs
Mobile Opacity and Visual Inspection for pre-OBD heavy-duty diesels. We bring the smoke meter and credentialed inspection to your yard, job site, or storage lot.
What OVI testing covers
Opacity + visual, done on-site
The Opacity and Visual Inspection is CARB's periodic compliance test for heavy-duty diesel engines that pre-date the 2013 OBD mandate. It combines a smoke-opacity reading with a physical inspection of emissions control components. We bring the certified smoke meter, the CARB-compliant procedure, and the paperwork to your location.
OVI is especially common for agricultural operators, construction fleets, vintage truck owners, and specialty rigs that still use 2012-and-older diesel engines. If your equipment runs a pre-2013 engine, you need OVI — an OBD test will not cover you.
Vehicles we test with OVI
- • 2012 and older heavy-duty diesel trucks (Class 7 & 8)
- • Older school buses, charter buses, and transit coaches
- • Pre-2013 RVs, motorhomes, and tour buses over 14,000 lbs GVWR
- • Vintage and legacy fleet vehicles still in commercial service
- • Agricultural, construction, and utility diesel rigs
How the test runs on-site
- 1. Vehicle warm-up. Engine brought to operating temperature before the opacity procedure begins.
- 2. Opacity measurement. Calibrated smoke meter placed in the exhaust stream. Engine is snap-accelerated; meter records each reading.
- 3. Visual inspection. Walk-around inspection of emissions hardware, EGR, DPF (if applicable), and signs of tampering or removal.
- 4. Documentation. Findings recorded on the CARB-compliant OVI form with photos where required.
- 5. Submission. Results submitted to CARB. Manual processing takes several business days.
Frequently asked questions
- What is OVI testing?
- OVI stands for Opacity and Visual Inspection. It is the CARB Clean Truck Check test for 2012 and older heavy-duty diesel engines that lack modern OBD-based emissions diagnostics. The procedure combines a smoke opacity meter reading with a physical inspection of visible emissions control components.
- Why does OVI take longer than OBD?
- OVI requires a physical smoke opacity test with multiple accelerations, plus a walk-around inspection of tampering indicators, exhaust modifications, and visible emissions control hardware. Budget 25 to 35 minutes per vehicle on average.
- How is a smoke opacity test performed?
- Our tester places a calibrated smoke opacity meter in or near the exhaust stream while the vehicle is held at operating temperature. The engine is snap-accelerated several times and the meter records the percentage of visible smoke. CARB sets pass/fail thresholds by engine model year.
- What causes an OVI failure?
- Most common reasons: excessive smoke opacity from worn injectors, clogged air intake, failed EGR components, or DPF issues. Tampering or removal of emissions hardware also causes an automatic fail on the visual portion.
- How quickly does an OVI pass clear a DMV hold?
- OVI results are manually processed by CARB. Pass confirmation and DMV release typically take several business days after test day, sometimes longer during peak periods. If you are under a time-sensitive hold, let us know and we can prioritize.
Get your older rig back in compliance
Mobile OVI testing for a single truck or a full legacy fleet. We handle the paperwork, you keep working.