Skip to main content
CARB Diesel Test

CARB Testing in Modesto

Mobile CARB testing for Modesto fleets and ag operations

We bring certified Clean Truck Check testing to Modesto yards, farms, and residential addresses. Both OBD and OVI handled on one visit.

CARB Credentialed Tester
200+ 5-Star Reviews
OBD & OVI Certified
Mobile Service Available

Mobile CARB testing for Modesto

Modesto sits at the heart of Central Valley agriculture, and the trucks that move the almonds, walnuts, stone fruit, dairy, and feed that come out of this region are a core part of our mobile CARB Clean Truck Check business. We handle modern 2013+ OBD-capable rigs and older pre-2013 equipment with equal capability, right at your location.

Where we dispatch in Modesto

We regularly serve the Highway 99 commercial corridor, the Beard Industrial District, warehouses along Crows Landing Road, the Modesto Airport industrial area, and ag operations throughout the surrounding area including Salida, Ceres, Riverbank, Empire, and Oakdale. Residential service for owner-operators is also common.

Built for ag fleets

Central Valley ag operations run trucks that are both essential and, in many cases, legacy equipment. We understand that. Our mobile service brings the full CARB Clean Truck Check procedure (both OBD for modern engines and OVI for older ones) to the farm, the yard, the processing facility, or the storage lot. No driving a truck you depend on to a testing shop, and no pulling dispatch off a critical lane.

Volume-friendly dispatch

Larger Modesto-area fleets typically book us for a day of staged testing: your drivers line up the trucks, our credentialed tester cycles through the procedure on each one, and you receive a single consolidated invoice at the end. Volume pricing applies above specific vehicle counts.

Book your Modesto visit

Modesto stops are scheduled 1 to 2 business days out, often batched with other Stockton and Ripon visits for efficiency. Call to get on the dispatch.

Local landmarks we dispatch near

  • Highway 99 commercial corridor
  • Beard Industrial District
  • Crows Landing Road warehouses
  • Modesto City-County Airport area
  • Downtown Modesto

Modesto industries we serve

  • Central Valley agricultural fleets
  • Almond, walnut, and produce haulers
  • Food processing and cold-chain logistics
  • Aggregate and ready-mix concrete
  • Dairy and feed delivery
  • Owner-operator long-haul

Frequently asked questions

Do you service ag operations outside Modesto city limits?
Yes. We regularly dispatch to farms, orchards, and ag yards in the Modesto area, including Salida, Ceres, Riverbank, and Oakdale. Provide the address when you book and we will confirm the drive time and scheduling window.
Can you OVI-test older ag trucks that rarely leave the farm?
Yes. A common scenario in Modesto is pre-2013 dump trucks, feed trucks, or bulk haulers that work primarily on ag operations. We bring the smoke opacity meter and run the full OVI procedure right at your operation.
What is the drive time from Sacramento to Modesto?
Roughly 75 to 90 minutes. We typically batch Modesto stops with other Central Valley visits on the same dispatch to make the trip efficient.
Does my Modesto truck need an OBD or OVI test?
It depends on your engine model year. Diesel engines from 2013 and newer take the electronic OBD test, and 2012 and older engines take the OVI smoke opacity and visual inspection. We are credentialed for both and bring the right equipment based on the engines you tell us about when booking your Modesto visit.
How much does CARB Clean Truck Check testing cost in Modesto?
There are two parts. CARB charges an annual compliance fee of $32.13 per vehicle in 2026, paid to the state. Separately, you pay for the test itself, which depends on the test type and vehicle count. Mobile pricing is consistent across our coverage area, and fleets scheduling several trucks in one visit qualify for volume rates. Call (916) 538-7777 for a quote.
How fast does a Modesto test clear my DMV registration hold?
For 2013 and newer engines passing the OBD test, we upload results during the visit and CARB releases compliance to the DMV the same business day in most cases, so a Modesto-registered rig can come off its hold within hours. OVI results take several business days for CARB to process.
What happens if my Modesto truck fails the test?
A failed test carries no fine by itself, but your DMV hold stays until you repair the issue and pass a retest. We tell you exactly what failed, point you to the specific OBD trouble code or OVI finding, and can recommend trusted diesel repair shops in the Modesto and Stanislaus County area. Once the fix is done, we come back and retest.
Are you actually CARB credentialed?
Yes. We are credentialed by the California Air Resources Board for both OBD testing and OVI opacity testing, and our credentials are verifiable on the CARB Clean Truck Check program registry. We provide credential numbers on request before any service visit.

Book Modesto mobile testing

Get a tester on your Modesto site

Tell us about your vehicles. We respond within 2 hours during business hours.

Or call us directly at (916) 538-7777. We typically respond within 2 hours during business hours.

Ready for mobile CARB testing in Modesto?

One call books one truck or an entire fleet.

Call (916) 538-7777 Request a Quote
Call Now Book Online