What Is the Difference Between OBD and Smoke Opacity Testing

OBD (On-Board Diagnostics) and Smoke Opacity Testing serve distinct purposes in ensuring diesel vehicles comply with CARB regulations. OBD testing examines a vehicle’s onboard computer system to detect emission-related issues, providing insight into potential malfunctions or inefficiencies. In contrast, Smoke Opacity Testing measures the amount of smoke emitted from the exhaust, evaluating the visible pollutants produced by the engine. OBD testing is commonly used for modern vehicles equipped with advanced diagnostic systems, while Smoke Opacity Testing is ideal for older diesel models without integrated electronics. Both tests are vital for reducing emissions, promoting environmental responsibility, and meeting California’s strict air quality standards. At Norcal Diesel Testing, we offer comprehensive mobile services for both OBD and Smoke Opacity Testing. Our experts bring these essential compliance tests directly to your location, whether it's your fleet yard, job site, or home. We make it easy to stay CARB-compliant without the hassle of visiting a testing station. Visit the Norcal Diesel Testing website to learn how we can help keep your vehicles compliant and running efficiently.