Emissions Testing in Indiana

Who Needs an Emissions Test or Smog Check

Indiana requires emissions testing only for vehicles registered in Lake County and Porter County. These vehicles must be gasoline powered, manufactured after 1975 and weigh 9,000 pounds or less. Vehicles in other parts of the state generally do not require testing.

How Often Tests Are Required

Vehicles in Lake and Porter counties must undergo testing every two years. Model year determines testing year parity, with even‑model years tested in even calendar years and odd‑model years in odd years. Testing must be completed before registration renewal.

Where Emissions Testing Is Required

Testing is only required in Lake County and Porter County in northwest Indiana. Other parts of the state, including central and southern regions, are exempt. Requirements may vary at the county level and could change, so confirm with official sources.

What Happens During the Test

At a testing station a certified inspector performs a visual inspection for tampering and intact emissions control equipment such as catalytic converter and fuel cap. The vehicle identification and registration documents are checked. Then the test typically uses an OBD‑II scan or relevant emissions procedure depending on model year, and may include tailpipe or evaporative system checks. Any failed component triggers a repair and retest requirement, documented on a Vehicle Inspection Report. Emissions testing requirements in Indiana follow state and federal standards to ensure readiness and compliance.

Areas in Indiana That Require Emissions Testing

Requirements for testing vary across Indiana depending on local air quality needs. Emissions testing locations in Indiana are concentrated in northwest counties that are part of the Chicago area, including listings in cities such as Indianapolis region suburbs, Greenwood, Michigan City, Plainfield, Noblesville, Carmel, Crawfordsville, Goshen and Gary. However testing remains mandatory in Lake and Porter counties only. Cities further from those counties typically do not require testing. Availability of certified stations aligns with these regional rules and urban density often means greater proximity to testing options.

How the Emissions Test Works in Indiana

When you take your vehicle to a testing station the process typically takes fifteen to thirty minutes. Bring your current registration or renewal notice and a form of identification. First the station verifies the vehicle’s model year, gross vehicle weight rating and VIN, then performs a visual check for tampering and emissions devices. The technician runs an OBD‑II diagnostic or tailpipe evaluation depending on age. If the vehicle fails, the report will list reasons like illuminated check engine light or incomplete readiness monitors. You must repair the issues and then return for a retest. Costs differ by station; there is no fixed fee mentioned here. If you fail repeatedly you may apply for a one‑time repairs waiver with documentation. A passing result yields a compliance certificate for registration.