CARB-Certified Diesel Smog Testing That Comes to You
On-site inspections completed in 15–20 minutes across Napa & Sonoma County.
No shop visits. No wasted time. No hassle.
$30 Travel + $80 Test
Per truck, same visit
3+ trucks: Travel fee waived
State-Certified CARB Tester • Full Compliance, Done Right
With a 20-year background in hospitality at luxury wineries in Napa Valley, I bring the same commitment to service excellence to mobile diesel smog testing.
When you need a Clean Truck Check in Napa or Sonoma County, you're getting a CARB-certified tester who understands the value of punctuality, professionalism, and making the process as smooth as possible.
I come to your location, complete your inspection in 15-20 minutes, and get you back to work. It's that simple.
Fill out the form below and we'll get back to you promptly
Got questions about Clean Truck Check testing in Napa or Sonoma County? Here are the answers fleet owners ask most.
A Clean Truck Check is a CARB-mandated diesel emissions test required for all commercial vehicles with a gross vehicle weight rating (GVWR) of 14,000 pounds or more operating in California. If you own or operate diesel trucks in Napa County, Sonoma County, or anywhere in California, you are required to pass this test to stay compliant. Non-compliant vehicles face fines up to $10,000 per vehicle per day and DMV registration holds.
As of 2026, most diesel vehicles require semi-annual testing — that means twice per year. Starting in October 2027, CARB is increasing the requirement to quarterly testing (four times per year) for OBD-equipped vehicles. Staying on top of your schedule now prevents costly penalties and registration blocks down the road.
You don't need to go anywhere — we come to you. Ramos NorCal Clean Truck Check provides mobile CARB-certified testing throughout Napa, Sonoma, American Canyon, Benicia, Yountville, Rutherford, Saint Helena, Calistoga, and surrounding North Bay areas. We test at your job site, yard, or wherever your trucks are parked.
Our first truck is $110 (includes a $30 travel fee plus $80 for testing). Each additional truck during the same visit is $80. For fleets of 3 or more trucks, the travel fee is waived — so every truck is just $80. No hidden fees, no surprises.
A typical Clean Truck Check inspection takes 15 to 20 minutes per vehicle. We arrive on time, perform the test on-site, and you receive your certification immediately. Most fleet visits are completed within a few hours depending on the number of trucks.
If a vehicle doesn't pass, we'll explain exactly what the issue is and what repairs are needed to bring it into compliance. Once repairs are completed, we can return to retest. It's important to address failures promptly — vehicles that miss their compliance deadline can face fines and DMV registration holds.
Yes. Diesel-powered motorhomes and recreational vehicles with a GVWR of 14,000 pounds or more are subject to Clean Truck Check requirements. We test RVs throughout Napa and Sonoma County — we'll come right to your home or storage location.
CARB can impose fines up to $10,000 per vehicle per day for non-compliance. Your vehicle's DMV registration can also be blocked until the issue is resolved, and out-of-state trucks may be restricted from operating in California. The compliance fee for 2026 is $32.13 per vehicle — a small price compared to the penalties.