Nevada Smog Check Program: A Complete Guide to Emissions Testing and Compliance

Unlike California, Nevada does not require smog checks statewide. Instead, Nevada operates a targeted Emission Control Program focused on areas where air quality is most affected by traffic and population density. If you live in or register a vehicle in certain parts of the state, emissions testing may be required for registration and renewal.

This guide explains who needs a smog check in Nevada, who is exempt, how the testing works, and what happens if your vehicle fails.

When Is an Emission Test Required in Nevada?

In Nevada, an emission inspection is required for:

Used motor-vehicle registrations

Each annual registration renewal, when applicable

Emission test results are:

Valid for 90 days, or

Valid for 180 days when accompanied by a Dealer Report of Sale

The Nevada DMV will notify you during renewal whether your vehicle requires an emissions test.

Which Vehicles Require a Smog Check?

Your vehicle requires an emission test if all of the following apply:

The vehicle is based in urban areas of Clark County or Washoe County

It is gasoline powered, or

Diesel powered with a GVWR up to and including 14,000 lbs

It is model year 1968 or newer

New vehicles on their fourth registration cycle

Hybrid vehicles on their sixth model year

Outside of Clark and Washoe Counties, most vehicles in Nevada do not require emissions testing.

Vehicles Exempt from Nevada Smog Checks

You are exempt from emissions testing if your vehicle is:

A new motor vehicle in its first, second, or third registration cycle

A hybrid-electric vehicle 5 model years or newer

Model year 1967 or older

A motorcycle, moped, or most trimobiles

Based in remote areas of Clark or Washoe County, or any other Nevada county

A diesel vehicle over 14,000 lbs GVWR

Powered strictly by propane, CNG, or electricity

Registered as Classic Rod, Classic Vehicle, or Old Timer and driven 5,000 miles or less per year

Certified by the DMV as a Replica Vehicle

Nevada licenses different types of emissions stations:

1G Stations

Perform emissions tests only

Cannot perform emission-related repairs

2G Stations

Perform emissions tests and emission-related repairs

Diesel Stations

Authorized to test diesel vehicles only

A full list of licensed stations is available on the Nevada DMV website

Nevada DMV Emission Labs

If you need assistance, challenge a test result, or request a waiver, Nevada operates DMV Emission Labs:

Las Vegas
2621 E. Sahara Ave., Las Vegas, NV
Phone: (702) 486-4981

Reno
9155 Double Diamond Pkwy, Reno, NV
Phone: (775) 684-3580

How Nevada Smog Tests Work

Gasoline Vehicles

1996 and newer: OBD-II diagnostic testing

Pre-1996 light-duty and heavy-duty vehicles: Two-speed idle test at ~2,500 RPM and idle

Visual inspection for tampering of:

Gas cap

Air injection system

EGR system

Catalytic converter

Fuel inlet restrictor

All gasoline vehicles are visually inspected for exhaust smoke and crankcase blow-by

Light-Duty Diesel Vehicles

Tested on a dynamometer

Opacity test plus visual inspection of emissions components

Not all stations can test 4WD or traction-control diesels; the DMV Emission Lab can assist with referrals

Rejected vs Failed Emission Tests

A rejected test is not a failure.

Common reasons for rejection include:

OBD monitors not ready (1996+ vehicles)

Engine RPM cannot be maintained within testing limits

If rejected:

You may need additional driving

Or a challenge test at a DMV Emission Lab

What Happens If Your Vehicle Fails?

If your vehicle fails:

Repairs must be completed

The vehicle must pass a second test

If it fails again, it may qualify for a waiver, depending on county and repair costs.

Waiver Requirements

Clark County

Repairs must be done at an authorized 2G station

Minimum $450 spent on emissions-related repairs

Vehicles with visible smoke, tampering, or warranty coverage are not eligible

Washoe County

Repairs may be done at a 2G station or by the owner

Minimum $200 in emissions-related repairs

Same exclusions apply

Smog Spotter Program

Nevada also operates Smog Spotter, a public reporting program allowing residents to report smoking vehicles:

Website: SmogSpotter.com

Statewide: 844-END-SMOG

Las Vegas: (702) 642-SMOG

Reno: (775) 686-SMOG

Final Thoughts

Nevada’s smog-check system is targeted, structured, and enforcement-driven through DMV registration. If you live in Clark or Washoe County, understanding whether your vehicle requires testing—and how that test works—can prevent delays, rejections, and unnecessary repairs.

When in doubt, your DMV renewal notice is the final authority, and the DMV Emission Labs are there to help resolve disputes.