Wisconsin requires emissions testing in two counties, and you must pass before you can register your vehicle

Wisconsin emissions testing is required only in Dane County (Madison area) and Milwaukee County. If you live in either county and own a vehicle model year 1968 or newer, you must pass an emissions test before you can register or renew your registration. The test checks whether your vehicle's exhaust meets state pollution standards.

If you live outside these two counties, you do not need an emissions test. Wisconsin does not have a statewide testing program. The requirement exists only in areas where air quality monitoring showed a need for vehicle emission controls.

You can take your test at any Wisconsin Department of Natural Resources (DNR) certified emissions testing station. These are private repair shops and service centers that have been trained and approved to run the test. The test itself takes about 10 minutes and costs between $10 and $20, depending on the station.

Key Takeaways

  • Emissions testing in Wisconsin is required only in Dane County and Milwaukee County; all other counties are exempt.
  • Your vehicle must pass the test before you can register or renew your registration with the Wisconsin Department of Motor Vehicles.
  • You can get tested at any DNR-certified emissions testing station, which are private shops and service centers throughout the two counties.
  • The test costs $10 to $20 and takes about 10 minutes; you will receive a pass or fail result on the spot.
  • If you fail, you have 30 days to repair your vehicle and retest at no additional charge at the same station.

How the Wisconsin emissions test works

The test measures the amount of nitrogen oxides (NOx), particulate matter, and other pollutants your vehicle releases. A technician will connect a probe to your vehicle's tailpipe and run the engine at idle and at a higher speed. The machine records the emissions levels and compares them to the standards set by the Wisconsin DNR.

You will receive a pass or fail result when ready. If you pass, the station will provide you with a test report that you need to show when you register your vehicle. If you fail, the station will give you a list of possible repairs and a 30-day window to fix the problem and retest.

Vehicles that are too old or too new may be exempt. Model year 1967 and older vehicles are not tested. Some newer vehicles with advanced emission control systems may also be exempt depending on their model year and the county where you live. The testing station can tell you whether your vehicle is exempt when you call or visit.

Finding a certified testing station in Dane County or Milwaukee County

The Wisconsin DNR maintains a list of certified emissions testing stations on its website. You can search by county and city to find stations near you. The list includes the station's address, phone number, and hours of operation.

Call ahead before you go. Many stations accept walk-ins, but some require an appointment, especially during busy seasons like spring and fall when many people renew their registrations. Ask about wait times and whether the station can test your specific vehicle type.

You will need to bring your vehicle keys and proof of ownership or registration. Some stations may ask for your vehicle identification number (VIN) when you call to schedule. Have that information ready.

What happens if you fail the emissions test

A failure does not prevent you from registering your vehicle when ready, but you will need to pass the test before your registration becomes valid. You have 30 days from the test date to repair your vehicle and retest at the same station at no additional charge.

Common reasons for failure include a faulty oxygen sensor, a malfunctioning catalytic converter, a check engine light that is on, or a fuel system leak. The testing station will provide a report listing which emissions standards your vehicle did not meet. This information can help a mechanic diagnose the problem.

If you repair your vehicle and retest within 30 days at the same station, you will not pay another testing fee. If you wait longer than 30 days or test at a different station, you will have to pay the full testing fee again.

Registering your vehicle after passing the test

Once you pass the emissions test, take your test report to the Wisconsin Department of Motor Vehicles when you register or renew your vehicle. You can register online, by mail, or in person at a DMV office. The test report is valid for 30 days, so do not wait too long after passing to complete your registration.

If you are registering online or by mail, you will need to include a copy of the test report with your registration documents. If you register in person, bring the original report. The DMV will not process your registration without proof that you passed the test.

Vehicles exempt from Wisconsin emissions testing

Model year 1967 and older vehicles do not require emissions testing, regardless of where you live in Wisconsin. Some newer vehicles may also be exempt depending on their model year and engine type. Diesel vehicles, motorcycles, and vehicles with certain engine sizes may have different requirements.

The best way to confirm whether your vehicle is exempt is to call a certified testing station or contact the Wisconsin DNR directly. Provide your vehicle's model year, make, model, and engine type. The station can tell you in one call whether you need to test.

Frequently Asked Questions

Do I need an emissions test if I live in Wisconsin but outside Dane or Milwaukee County?

No. Wisconsin only requires emissions testing in Dane County and Milwaukee County. If you live anywhere else in the state, you do not need to test your vehicle before registration, regardless of its age or condition.

What if I move to Dane or Milwaukee County after registering my vehicle elsewhere?

When you renew your registration in the new county, you will need to pass an emissions test first. If you move mid-registration period, contact the Wisconsin DMV to learn whether you need to test before your next renewal or if you can wait until your current registration expires.

Can I test my vehicle at any repair shop, or does it have to be a DNR-certified station?

It must be a DNR-certified station. Only certified stations have the equipment and training to run an official test that the Wisconsin DMV will accept. A regular repair shop cannot perform the test even if they have similar equipment.

What if I fail the test and cannot afford the repairs?

You have 30 days to repair and retest at no additional charge. If repairs are expensive, you can get a second opinion from another mechanic. Some nonprofits and community programs in Wisconsin offer low-cost repair information, though availability varies by county. Contact your local community action agency to ask about repair help programs.

Is the 30-day retest window the same at every station?

Yes. Wisconsin DNR rules require all certified stations to allow a free retest within 30 days of a failure at the same station. If you test at a different station after 30 days, you will pay the full fee again.