A diesel smog check ensures compliance with emission standards by inspecting the OBD system, exhaust, and emissions components. No tailpipe test is required—only OBD and visual inspections.
A parked beige and white Class C motorhome RV in a parking lot with design patterns on its side, surrounded by trees and cars.
A Check Engine Light (CEL) and OBD II check for diesel vehicles, RVs, and heavy-duty trucks works like a regular smog check by scanning the OBD system for emission-related faults. It checks trouble codes, readiness monitors, and system malfunctions t
A diesel smog check requires the vehicle to have no visible smoke from the tailpipe. Excessive smoke indicates engine or emissions issues and will result in a failed inspection.
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An EGR (Exhaust Gas Recirculation) check for older, non-dyno vehicles like heavy-duty gas vehicles and RVs involves inspecting the EGR valve and related components for proper function. Technicians check that the valve is not clogged or stuck and conf
Orange Ford F-750 dump truck parked on pavement.
Ignition timing for older RVs and heavy-duty vehicles is checked similarly to a regular smog check. Technicians verify that the timing is set correctly to ensure the engine runs efficiently and produces lower emissions. If the timing is off, it can l
An RV smog check verifies compliance with emission standards by inspecting the emissions components, exhaust, and Check Engine Light (MIL). It includes a visual inspection, functional testing of components, and a tailpipe test for gasoline-powered RV
Gas-powered vehicles over 14,000 GVWR require an emissions test because they are subject to stricter environmental regulations due to their higher emissions potential. These larger vehicles, like heavy-duty trucks and RVs, are inspected to ensure the
Truck with open hood in garage, equipped with snow plow attachment.
Dodge Ram Cummins Turbo Diesel engine under car hood.
A white utility bucket truck with an elevated work platform, parked on a paved surface, with a brick wall and trees in the background.
Yellow school bus parked outside, labeled with "Justin-Siena High School."
Truck in a garage with hood open, undergoing maintenance.

Diesel/Rv’s/Heavy Duty Vehicles

Smog Check for Diesel, RVs, and Heavy-Duty Vehicles

Diesel vehicles, gasoline RVs, and gasoline heavy-duty vehicles also require a smog check, but the process differs from standard cars.

  • Diesel Vehicles (1998 & Newer) – Must be tested if they have a Gross Vehicle Weight Rating (GVWR) under 14,000 pounds. The check includes an OBD test, a visual inspection of emissions components, and a check for visible smoke.

  • Gasoline RVs & Heavy-Duty Vehicles – Must undergo a smog check, which includes an OBD test, an emissions check, and a functional inspection to ensure the emissions system is working properly.

Inspection fee

1998 & Newer Diesel: $60

Heavy Duty Vehicles: $60

Motorhomes: $100