Compliance made easy.

We come to you!

If your diesel vehicle needs a smoke opacity test, you don’t have time to waste. At Darling Smog, we offer mobile CARB-compliant smoke opacity testing for trucks, fleets, and RVs (and more!) anywhere in Glendora, the San Gabriel Valley, or Greater LA.

We’re a woman and veteran-owned shop that understands the pressure to stay compliant without losing a day of work. That’s why we bring the test site to you.

What We Test:

2012 and older vehicles that need smoke opacity and visual tests
2013+ vehicles that need OBD II testing
And alternative fuel vehicles that need visual inspections

Where We Go:

We offer on-site mobile testing throughout:

Glendora, Covina, Azusa, La Verne

Los Angeles & San Gabriel Valley

Job sites, yards, terminals, and even parking lots

Why Choose Darling Smog?

✅ Fully CARB-compliant
✅ Fast, mobile appointments
✅ No upsells, only testing

✅ Same-day and emergency slots may be available—please call or inquire online

We’re licensed, friendly, and efficient. You’ll always know what to expect. We’re here to make compliance easy. 

Ready to Book?

Whether you’re managing a fleet or just need your RV tested before hitting the road, we’re ready to meet you where you are.

 Call us at 626-551-4555 or
Book your mobile smoke opacity test here.

Let’s clear the air, one truck at a time.