Auto Squad DB
“My frs threw a code recently and these guys were able to diagnose it quickly and set me up with an appointment ASAP.”
Best Car Inspection & Emissions Testing near Diamond Bar, CA
We have 2 stations in Diamond Bar on file, and both are on this list, along with 13 from towns including Upland (4, 12 mi), Ontario (2, 12 mi) and La Puente (1, 5 mi).
1 open 24/7 · 13 open weekends · 14 rated 4.5+ · 4 show a license
Data verified October 16, 2026
Diamond Bar Auto Service & Body
“The boss is always so kind”
Foothill Quicky Smog
“We take all our work vehicles here and they get us in and out- the wait is never long.”
Mobile Mechanic Pros Ontario
“This mobile mechanic did an absolutely outstanding job on my vehicle today.”
Smog N Save
“Dude has a great personality and with no line, he got me in n out of the shop in less than an hour.”
Pomona Gear
“Sam was honest and upfront with us on the issue on our jeep.”
Listed for drivers in and around Diamond Bar, CA, these 15 shops carry out emissions and inspection work. What each one says about its station license, hours and retest policy comes from its own website; ratings and quotes come from public reviews.
Area overview: Diamond Bar, CA
The 15 stations on this page are rated from 4.1 to 4.9 across 3,414 reviews; 14 have 50 or more reviews and 14 are rated 4.5 or higher. The topics that come up most in reviews of the stations on this page are "price" and "fair". 1 is open around the clock; 13 are open on Saturdays and 3 on Sundays. 4 show a license on their websites; 2 list staff certifications (ASE) and 10 have a BBB rating of A or A+. 12 have ten or more years of experience, the longest 63 years. 1 offers emergency or roadside call-outs; 2 give free estimates; 5 are family- or locally-owned and 4 list coupons or special offers. We have a website on file for 13 of the stations on this page; 8 publish a contact page; 5 list a public email and 3 take bookings online. We count these figures across the stations on this page; distances are straight-line, and hours and prices change, so confirm the details with the station before you visit.
Can I use a station outside Diamond Bar?
Inside your own state, yes. 2 of the 15 shops here are in Diamond Bar and the rest come from other towns. Crossing a state line does not work, because the test has to be accepted by the state that registers the car.
VMS Auto Collision Center
“Excellent service , this is the 4th van from my fleet that VMS has repaired always on time and done right the first time .”
小李修車廠 KB Motor
“The boss is very enthusiastic and nice, and he taught me a lot about cars.”
North El Monte Automotive
“This was a Major service, changing all the belts, timing belt,back brakes, new radiator,oil change,smog check.”
Low Price Smog Check
“They are very friendly fast and on and out in bout 10 mins thank you will send more your way”
R & N Complete Auto Repair
“By far the best experience I've had dealing with a mechanic and I'm going to keep coming back.”
Al & Lee's Auto Care Center
“I have taken my car to him at least 3 times and always have ;even happy w his service and prices .”
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Connie & Dick's Auto Service Center Inc.
“Customer service is second to none, 100% confident all recommendations are required.”
Smog Tech Star Station
“I had a great experience coming here this morning; they provided fast service at a reasonable price.”
Z Smog Check
“They're super quick and friendly here, I got my smog done in 30 minutes”
Why these companies made our list
What customers say about stations near Diamond Bar
- “This is only place I trust to send my car over if it needs to be fixed or maintained!” — customer of Auto Squad DB
- “I brought my vehicle in to have my passenger window motor and headlights replaced and R and N came through with a great price and quick repair time, Rafe and his experienced team are on point and really know what they are doing.” — customer of R & N Complete Auto Repair
- “My favorite smog shop, convenient and fast! Knowledgeable guys that help us out with all of our cars, gets them in and out very quickly.” — customer of Low Price Smog Check
- “This place is great to deal with. The people are friendly, the smog is done quickly, and the prices are really reasonable.” — customer of Foothill Quicky Smog
- “I highly recommend this place, if you need a smog come support a small family business.” — customer of Z Smog Check
Excerpts from public reviews of the stations listed on this page.
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