About the Test

The Gateway Vehicle Inspection Program is part of Missouri’s continuing effort to improve air quality in the St. Louis region. The Gateway Vehicle Inspection Program is a combined emissions testing and safety inspection program for vehicles registered in the St. Louis ozone nonattainment area. The nonattainment area includes St. Louis City and Franklin, Jefferson, St. Charles and St. Louis counties.

Testing Information

Where can I go to have my vehicle emissions tested?
The state is licensing auto shops in the St. Louis area to conduct the emissions testing. All currently licensed safety inspection stations are encouraged to participate in the program

Find a GVIP Station Near You

What is the cost of an emissions test?
The emissions testing fee shall not exceed $24, and the safety inspection fee shall not exceed $12. The station shall determine the acceptable forms of payment. The fees shall include one free reinspection, if the same licensed station conducts it within 20 business days.

Emissions Testing Procedure

How are vehicle's emissions tested?
The Gateway Vehicle Inspection Program will use On-Board Diagnostics or OBDII testing to conduct the emissions test. This testing method accesses an advanced computer system installed in all 1996 and newer gas-powered and 1997 and newer diesel-powered vehicles 8,500 pounds or less in Gross Vehicle Weight Rating. OBDII is an early-warning system that continually monitors the vehicle’s emissions-control devices and other engine-related components to ensure all are functioning properly.

When the vehicle is presented for an emissions test, an inspector will attach a connector cable to the OBD port generally located below the dash on the driver’s side of the vehicle. The connector has several ports and looks similar to the illustration below.

OBD Connector image

Any emissions-related OBD diagnostic trouble codes or other OBD failures will be printed on the Vehicle Inspection Report.

OBDII systems provide valuable emissions information that allows motorists to invest in needed repairs and preventive maintenance to ensure that their vehicle continues to perform efficiently. The outcome of the Gateway Vehicle Inspection Program will be cleaner cars on the road and cleaner air for everyone to breathe. For more information see On–Board Diagnostics (OBDII) Fact Sheet.

If my vehicle fails, where can I go to have it repaired?
Anyone may perform necessary repairs for the vehicle. Customers are not required to have repairs completed at the station that performs their vehicle’s emissions test. It is important to note that waiver criteria may affect where a motorist chooses to have repairs performed. For more information see Waiver Criteria or Failed Vehicles.

Your vehicle inspection report is valid for registration purposes for 60 days from the date the vehicle passes the test or receives a waiver.

Emissions Retesting Procedure

What is required for retesting my vehicle?
If your vehicle has been repaired, it’s time to get ready for a retest. Retests are required until your vehicle passes or until you obtain a waiver from the Missouri Department of Natural Resources.

Once repairs are completed, the motorist must return to the initial testing station within 20 business days of the intitial test date to qualify for one free reinspection. If you miss the 20 business days timeframe, you will be required to pay the full testing fee again.

The vehicle owner must present to the station the previous vehicle inspection report and the completed repair data sheet that your repair technician filled out and signed. Note that only the labor charges made by a Missouri Recognized Repair Technician (MRRT) will count toward the minimum waiver expenditure requirements.

About the Repair Data Sheet
The Repair Data Sheet is used to gather necessary information about the specific repairs on a vehicle that has failed an emissions test. In order to properly process a retest and give credit for the repair to a specific repair facility, the back of the form must be properly filled out.

The repair information is used in calculating the Repair Effectiveness Index (REI) published in the Repair Facility Performance Report (RFPR). Several factors are taken into account when computing the REI. The calculation is essentially the number of successful/passing emissions repairs divided by the number of total emissions repairs. The report covers repairs performed over a designated 6-month period. In order to qualify for an REI score a repair facility must have 12 or more emissions-related repairs on file with the program for the designated period.

Note: any repair where the Repair Data Sheet has been completed with the "No" box filled in - indicating that not all recommended repairs were performed - will NOT count for or against a shop's REI score.

The repair information must be filled in completely as indicated by writing figures in the boxes and filling in the circles solidly with black or dark blue pen (felt-tip pens work well). If all sections are not completed carefully, inaccurate information will adversely affect a repair facility’s REI rating.

Before you retest...drive your repaired vehicle normally for several days before returning to the station that initially performed the emissions test. Doing so can help reset your vehicle’s readiness monitors. For more information on readiness see the On–Board Diagnostics (OBDII) Fact Sheet.

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