Hear from Our Customers
You’re running a business, not playing catch-up with California regulations. Every day a truck sits waiting for CARB compliance testing is a day you’re losing money—somewhere between $450 and $760 per vehicle if we’re being honest about real downtime costs.
The Clean Truck Check program isn’t optional anymore. If your semi truck is model year 2013 or newer and weighs over 14,000 pounds GVWR, you need testing every six months starting this year. Miss it, and you’re looking at DMV registration holds, port access denials, and fines that start at $1,000 and climb to $10,000 per vehicle per day.
We handle CARB certified smog checks on-site at your Los Angeles facility or yard. The OBD testing takes about 15 minutes per truck. Results upload to the CARB database immediately. You get compliance confirmation in real time, and your trucks stay on the road where they belong.
All SMOG Motors focuses exclusively on CARB emissions testing for heavy-duty trucks in Los Angeles. We’re not a general repair shop trying to squeeze in compliance work between oil changes. This is what we do.
Our testers are CARB credentialed with over 20 years of combined experience in California’s heavy-duty inspection program. We use CARB-certified OBD testing equipment, and we know the regulations inside out because we work with them every single day.
Los Angeles has roughly a million heavy-duty trucks and buses that fall under this program. The port traffic alone creates massive demand for reliable, fast compliance testing. We built our service around what fleet operators and owner-operators in this market actually need—mobile testing that doesn’t disrupt operations.
You schedule a time that works for your operation. We drive to your Los Angeles location with our CARB-certified testing equipment. No need to take trucks off route or send drivers across town to a testing station.
Our credentialed tester connects to your truck’s OBD system and runs the emissions diagnostic. For 2013 and newer diesel engines, this is a straightforward electronic check of your emissions control systems. The test typically wraps up in about 15 minutes per vehicle.
Results go straight to the CARB database the moment testing is complete. You get immediate confirmation of compliance status. If your truck passes, you pay for the test. If it doesn’t pass, you don’t pay—though travel fees may apply depending on location.
If a vehicle fails, you’ll know exactly what triggered it. Most failures relate to check engine lights, DPF issues, or other emissions system faults that need repair before retesting. We’ll walk you through what needs to happen next.
Ready to get started?
This service applies specifically to semi trucks and heavy-duty vehicles that are model year 2013 or newer with a GVWR over 14,000 pounds. If your truck doesn’t meet both criteria, this isn’t the right program. Older trucks and lighter vehicles fall under different California regulations.
You’re getting mobile CARB emissions testing performed by credentialed testers using approved OBD diagnostic equipment. The test checks your emissions control systems—things like your diesel particulate filter, NOx sensors, and exhaust aftertreatment components. California requires this because heavy-duty vehicles make up only 3% of vehicles on the road but generate more than 50% of nitrogen oxide and diesel particulate pollution from mobile sources.
Los Angeles sees particularly heavy enforcement because of port operations, freight corridors, and air quality challenges. Non-compliant trucks get flagged at weigh stations, denied port access, and hit with registration blocks. The twice-yearly testing requirement means you need a testing provider you can count on when deadlines approach.
We schedule around your operation. Early morning, late afternoon, whatever minimizes disruption. You don’t pay unless your vehicle passes. And because we’re mobile, you’re not burning half a day driving trucks to a testing facility and waiting in line.
Mobile CARB emissions testing typically runs around $150 per vehicle in the Los Angeles area. Some companies charge less for high-volume fleet testing, with prices dropping to $95-125 per truck when you’re testing multiple vehicles at once.
Here’s the important part: we only charge if your truck passes. If the vehicle fails the Clean Truck Check, you don’t pay for the test itself, though travel fees may apply depending on your location. That’s different from most testing stations where you pay regardless of the outcome.
The real cost isn’t the test fee—it’s what happens if you skip testing or fail to maintain compliance. DMV registration holds mean your truck can’t legally operate in California. Port access gets denied. And CARB fines start at $1,000 per vehicle and can hit $10,000 per vehicle per day for serious violations. A $150 test twice a year is cheap insurance against those consequences.
The Clean Truck Check program applies to heavy-duty trucks that meet two specific criteria: model year 2013 or newer, and gross vehicle weight rating over 14,000 pounds. Both conditions must be true. If your truck is older than 2013 or weighs less than 14,000 pounds GVWR, different regulations apply.
This covers most semi trucks, large commercial vehicles, heavy-duty diesel trucks, and CNG trucks operating in California. The 2013 cutoff matters because that’s when OBD systems became standard on heavy-duty diesel engines, which is what the testing equipment checks.
The program applies whether you’re based in California or just operating here. Out-of-state trucks working in California need the same twice-yearly testing. This catches a lot of interstate operators off guard, especially those running port drayage or freight routes through Los Angeles. Testing became mandatory October 1, 2024, with the first compliance deadline hitting January 1, 2025.
Every six months. The Heavy-Duty Inspection and Maintenance program requires semi-annual emissions testing for all qualifying heavy-duty vehicles. That’s twice a year, every year, as long as you’re operating in California.
CARB set up the six-month interval because emissions control systems can degrade over time, especially on trucks running heavy miles. The frequent testing catches problems early—things like failing DPF regens, faulty NOx sensors, or check engine lights that drivers might ignore. Catching these issues before they become major failures keeps trucks compliant and prevents expensive repairs down the line.
Your test results stay in the CARB database, and enforcement happens at weigh stations, port gates, and during roadside inspections. Miss a testing deadline and your DMV registration gets flagged. That means no renewals, no legal operation, and potential impound if you’re caught running a non-compliant vehicle. The six-month schedule is tight, but it’s the law.
You’ll get a detailed report showing exactly what triggered the failure. Most failures come from check engine lights, diesel particulate filter issues, or problems with exhaust aftertreatment systems. The OBD test pulls diagnostic codes directly from your truck’s computer, so there’s no guessing.
Once you know what’s wrong, you need to get it repaired. Take the truck to a qualified diesel mechanic who can address the specific emissions system fault. After repairs are complete, you schedule a retest. With us, you don’t pay for tests you don’t pass, so the retest after repairs is when the charge applies.
Here’s what you can’t do: keep operating the truck without fixing it. A failed test means you’re not compliant, and that status shows up in the CARB database immediately. Weigh stations can see it. Port authorities can see it. And if you’re caught operating a non-compliant vehicle, you’re looking at fines and potential vehicle impound. Get it fixed, get it retested, get back to work.
Yes. That’s exactly why mobile testing exists. We bring CARB-certified OBD testing equipment directly to your yard, warehouse, or facility anywhere in Los Angeles. Your trucks stay on-site, your drivers stay productive, and you avoid the logistical nightmare of routing vehicles to a testing station during business hours.
Mobile testing makes particular sense for fleet operators running multiple trucks. Instead of pulling vehicles off routes one at a time over several days, you schedule a single appointment and we test your entire fleet on-site. The process takes about 15 minutes per truck, and results upload to CARB immediately.
For owner-operators or smaller operations, mobile service means you’re not losing half a day to drive across Los Angeles, wait in line at a testing facility, and drive back. We work around your schedule—early morning before runs start, late afternoon after trucks return, whatever works. The convenience factor is significant when you’re trying to run a business and stay compliant without sacrificing revenue days.
Yes, if they meet the program requirements. Any heavy-duty truck over 14,000 pounds GVWR from model year 2013 or newer needs Clean Truck Check testing if it operates in California—regardless of where it’s registered. This surprises a lot of interstate carriers, but California regulations apply to all trucks working within state borders.
If you’re running freight into Los Angeles ports, making deliveries in California, or passing through on interstate routes, you need testing every six months. CARB enforcement happens at weigh stations, border crossings, and port gates. Out-of-state plates don’t exempt you.
The practical challenge for out-of-state operators is finding testing when you’re not based here. That’s where mobile testing helps. If you’re in Los Angeles on a regular route, we can meet you at a truck stop, customer facility, or wherever your truck is parked. Get tested, get compliant, and avoid the registration holds and port access denials that shut down operations fast.
Local Resources
Useful Links
Other Services we provide in Los Angeles
