• Billy Hillmuth III

What To Do If Your Car Fails A MD Emissions Test

Updated: Aug 5


You roll into the Maryland emissions testing facility early Saturday morning. Your emissions test notice is about to expire in a few days, so you need to get this done. You pull into the testing area, hand your paper to the technician, pay your fee… and your car fails the test.


Now instead of grabbing a pancake breakfast at IHOP, you are stressing out about what to do next. Don’t be! At Hillmuth Auto Care, we work on cars that failed emissions on a daily basis, and we can tell you that it’s not the end of the world. If you find yourself in this situation, just follow these steps and you will be fine!


Take Your VEIC to Your Maryland Mechanic

Whether your vehicle passes or fails, you will get a Vehicle Emissions Inspection Certificate (VEIC) and a diagnostics report. They will have some information about why and to what extent your car failed the test.


Take this information along with your car to an auto repair shop that does emissions repair in Maryland. Don’t delay, because it’s in your best interest to complete the repair before the “valid through” date on the VEIC. This way you can re-test your car for free and avoid the late fees.


Why Did My Car Fail the Emissions Test?

Emissions test are designed to check the level of pollutants your car produces during fuel combustion. Depending on your car’s weight and manufacturing date, you may be subject to one or several tests.


These tests will show whether your vehicle’s emissions system is performing at its top efficiency and whether the emitted pollutants, such as carbon dioxide (CO2) and hydrocarbons (HC) are within the accepted standards.


Common Reasons for Vehicle Emissions Test Failure


Hydrocarbon Failure

This can be caused by any of the following:

  1. Air-to-fuel mixture ratio is too rich or too lean

  2. PCV valve malfunctioning

  3. A vacuum leak in the system

  4. Clogged catalytic converter

  5. Engine sensors malfunctioning

Sample Dilution Failure

This occurs when the carbon monoxide and carbon dioxide measurement is under 6% and an accurate exhaust sample cannot be taken from your vehicle. This is usually the indication of a leak in the exhaust system.


On-Board Diagnostics Failure

Your vehicle’s on-board diagnostic system has found malfunctioning emissions control components. A faulty malfunction indicator light on your dashboard could also cause this type of emissions test failure.


Carbon Monoxide Failure

This can be caused by any of the following:

  1. Incorrect idle speed

  2. Clogged air filter

  3. Air-to-fuel mixture is too rich

  4. Engine oil needs changing (is too dirty)

  5. Malfunctioning choke or PCV valve

Emissions Control Equipment Failure

Vehicles are designed with special equipment to control the emissions they produce. If these emissions controls have been removed or disconnected from the vehicle, it will not pass inspection.


Gas Cap Failure

Gas caps aren’t universal – your vehicle’s gas cap was made to fit your gas tank specifically, and if it has been damaged or improperly replaced, it can leak vapors and cause it to fail emissions testing.


As you can see, many vehicles’ systems from fuel injection to the engine and exhaust have direct or indirect effect on the outcome of your emissions test. Essentially, every component that handles the fuel from the point of entry as liquid to the point of exit as gas could potentially malfunction or fail.


If your check engine light is on, your vehicle will fail the emissions test—don’t even bother taking your car to the testing facility. Instead, bring it to your local Maryland auto repair shop and have the problem fixed ASAP.


If your car fails emissions out of the blue (which is how it usually happens), it’s not always a bad thing. You might have to go through the hassle of repair and re-testing, but at least you are now aware of the fact that your car is not performing efficiently. And because emissions problems often go back to the engine, you could be a few miles away from getting stranded in the middle of a highway. All of these possible vehicle issues can be avoided with regular maintenance visits to your local auto mechanic.


What Do You Do With a Failed MD Emissions Test?

If you’re not a professional car mechanic, it’s not easy to figure out on your own which of these is responsible for your vehicle not passing the Maryland emissions test.


The quickest and easiest way to get your vehicle in the right condition to pass is to take it to a reliable Maryland auto mechanic. Here, your car will undergo diagnostic testing so that the issue can be found and repaired.


Get Your Car Re-Tested

Your Maryland auto repair shop will probably have the necessary equipment to test your vehicle on site. But to get the green light from the MVA, you have to go back to your local VEIP station for re-testing.


If the time permits, allow a week or so after the repair is complete and before testing emissions again. This will ensure that your car’s on-board diagnostics monitors have enough time to reset themselves after any error codes have been cleared.


What if it Fails Again?

If you took your car to Hillmuth Automotive the first time, you don’t have to worry about failing the second test. But maybe you did some DIY repairs with the help of YouTube videos and it didn’t work—now what?


If this happens, you can obtain a repair waiver. This document will allow you to drive for two years without having to pass emissions test. This should give you plenty of time to figure out what’s wrong. To qualify for the waiver, you need to have completed emissions repairs totaling at least $450 and have the receipts to show for it.


Has your vehicle failed the MD emissions test? Contact the professionals at Hillmuth Auto Care to set up a diagnostic test today! We have four convenient locations in Clarksville, Columbia, Gaithersburg and Glenwood.