Mobile CARB Clean Truck Check across Modesto, Turlock, Merced and Ceres. We test diesel trucks at your dairy, processing plant, ranch or yard. No travel fees, no station trips.
The Modesto-to-Merced stretch of Highway 99 is the heart of California's dairy and ag economy. Stanislaus and Merced counties run on feed trucks, milk tankers, almond and nut haulers, and the freight that moves it all — and a lot of that equipment is older diesel that needs a SAE J1667 smoke opacity test. We bring mobile CARB Clean Truck Check straight to your operation in Modesto, Turlock, Merced and Ceres, plus Atwater, Livingston, Patterson, Oakdale, Riverbank and Los Banos.
Hauling oversized ag equipment to a distant testing station costs you a working day. Instead, we come down Highway 99, Highway 132, Highway 140 or out to the I-5 west side and test where the trucks already are — the dairy, the ranch, the plant yard. Check your VIN status first at carbcleantruckcheck.app, then call to book.
Same price at a Modesto plant or a Merced County dairy — no travel fees, no facility charges.
On-board diagnostics test for 2013-and-newer diesel engines. Fast plug-in, results uploaded to CARB.
Opacity / visual inspection tier of Clean Truck Check. Call and we'll confirm the right test for your truck.
Snap-acceleration smoke opacity test for 2012-and-older diesel engines that can't run OBD.
Mobile diesel motorhome testing at your driveway, storage lot or RV park.
Running a dairy or ag fleet? Call 916-890-4427 for fleet pricing → See the full Clean Truck Check rates.
If your diesel engine is 2013 model year or newer, it has an on-board diagnostics port. We plug in, pull the emissions data and submit it to CARB. Most newer tractors and box trucks are done in minutes.
If your engine is 2012 or older — which covers a lot of valley feed trucks and farm haulers — there's no OBD data to read, so it gets a SAE J1667 snap-acceleration smoke opacity test instead. Not sure which applies? Call and read us the engine year.
Stanislaus and Merced are among the top dairy counties in California. We bring J1667 smoke testing right to the dairy for feed trucks, milk tankers and silage haulers.
Harvest and hulling season runs hard on older diesel haulers. We test at the ranch, the huller or the cold-storage yard so trucks stay rolling through the season.
Modesto and Turlock are processing towns — beverage, poultry and food plants like E&J Gallo and Foster Farms run big fleets. We test at the plant during shift changes.
The I-5 distribution centers around Patterson and Los Banos move freight all over the state. We test box trucks and tractors right at the DC dock.
Merced and Atwater are growing fast around UC Merced. Dump trucks, water trucks and equipment haulers get tested on the active job site.
One truck parked at home in Ceres, Oakdale or Livingston? We'll come to your place or a nearby lot. No fleet required.
Primary cities below, plus the surrounding Stanislaus and Merced County towns. Don't see yours? Call — we likely cover it.
We test 7 days a week, including Saturdays, with early-morning and evening appointments so trucks aren't sitting idle during a paying shift or mid-harvest. Tell us when the trucks are back at the dairy, the plant or the yard and we'll work around it. Same-week and next-day slots are usually available across the Modesto-Merced area.
Yes — that's exactly what we do. Older feed trucks and farm haulers usually need the SAE J1667 smoke opacity test, and you shouldn't have to haul them to a station. We come to the dairy or ranch anywhere in Stanislaus and Merced counties and test on-site.
We do. We'll come to your Modesto, Turlock or Livingston plant and run the fleet during a shift change or loading window so production keeps moving. Call for fleet pricing on multi-truck visits.
Yes. The I-5 west-side corridor through Patterson and Los Banos is in our Central Valley zone. We test box trucks and tractors right at the distribution center so drivers stay on dispatch.
We cover the neighboring regions too. Jump to the nearest zone:
Call or text to schedule mobile CARB Clean Truck Check testing at your location — Modesto, Turlock, Merced or Ceres. Dairy, ag and fleet pricing available.
