Failing emission tests can be quite perturbing, unnerving, and frustrating. Did you have a failed emission inspection and wonder, ‘why the emission failure?’
A failed emission may make you feel like the inspectors are trying tricks on you, especially when your baby ride is running smoothly. But how do you know what’s wrong with your vehicle?
This article has provided sufficient information on the reasons for a failed emission test and how to fix it. Grab a seat; let’s reveal them.
What is an Emission Inspection?
An emission Inspection checks how much pollution your car puts out. It’s a way to ensure cars aren’t harming the air we breathe. When you take your vehicle for this test, mechanics examine the gases coming from your exhaust pipe.
The main goal of these tests is to keep our air clean. Cars can release harmful substances that are bad for people and the environment.
By testing cars, we can identify those polluting the air too much, which will help everyone breathe cleaner air.
These tests also push car makers to build cleaner cars. They have to make sure their new vehicles will pass these tests. This means newer cars often run cleaner than older ones.
You must pass this test in many places to keep driving your car legally. Caring for your vehicle and doing your bit for cleaner air is part of caring for your car.
How Do Emissions Inspection Work?
Emissions Inspection are designed to ensure that your vehicle isn’t releasing harmful pollutants into the air. There are two main types of tests, depending on the age of your car: the OBD (On-Board Diagnostic) check and the I/M240 dynamometer test.
The OBD check is used for vehicles made from 1996 onward and connects to the car’s computer to verify that all emissions-related systems are working properly.
For cars made between 1981 and 1995, the I/M240 test is used. This involves putting the car on a machine that simulates driving conditions while measuring the exhaust gases to check for pollution levels.
Aside from these two core tests, there are a few others that can be used, depending on the vehicle and your region:
- Some states require a visual inspection of the vehicle’s emissions components like the catalytic converter to ensure they are in place and working properly.
- A two-speed idle (TSI) test may be used for older models that don’t have OBD systems, testing exhaust emissions at both idle and at higher RPMs.
- An ASM, or Acceleration Simulation Mode, test also uses a dynamometer, testing emissions at idle and simulated driving conditions.
In some states, a gas cap pressure test checks for leaks in the gas cap, which can allow fuel vapors to escape into the air and increase emissions.
Why is an emissions Inspection important?
The exhaust that comes from the tailpipe on your vehicle has the potential to impact the quality of the air you breathe. That is especially true if you live in a densely populated area, such as in a large city.
Carbon monoxide (CO) is an invisible gas that results from incomplete combustion. CO is extremely toxic to humans.
Most modern engines curb the amount of CO that is emitted, but if your engine is not running properly (or if it is in an older vehicle), CO levels might be higher than normal.
Benzene is another ingredient in the automotive exhaust cocktail. Benzene is a known carcinogenic, and high levels of inhalation can significantly impair your health.
And hydrocarbons that escape from the tailpipe or evaporate are also detrimental to your wellbeing.
Health is not the only victim of pollution. Greenhouse gases and other compounds that come from your engine can also wreak havoc on the environment. Carbon dioxide (CO2) has long been thought to be a major contributor to climate change.
Nitrogen oxides are highly reactive and contribute to smog. Sulfur dioxide forms acids when burned and can lead not only to smog but engine corrosion.
Beyond the health and environmental implications of emissions testing, the process can also help to identify potential problems with your engine. An excess of pollutants can alert a technician to needed maintenance that can prevent mechanical failure in the future.
Why A Vehicle Fails An Emission Inspection?
There are a variety of reasons cars fail an inspection, some more easily resolved than others. Below are some of the common reasons for failed emissions tests:
#1. Recent battery disconnection.
Batteries that have been disconnected, such as during repairs, within a few weeks of getting your vehicle inspection may not have enough information stored within your onboard diagnostics system for the inspection, resulting in a failed emissions test.
#2. Issues with the data link connector (DLC).
Also known as the onboard diagnostics port, the data link connector is how the vehicle connects to an inspector’s testing system. Any kind of issues with the port or the connection can result in test failure.
#3. The “check engine” light is on.
If your check engine light is on, more than likely the inspection will result in a fail regardless of the reason it is lit.
#4. Diagnostic trouble code is identified.
The inspection may end up throwing a diagnostic trouble code in the inspection report. While disappointing, the report can simply be taken to a qualified mechanic who can identify the necessary services or repairs needed before your retest.
#5. Issues with the exhaust system.
Your vehicle’s exhaust system is responsible for taking the burnt gases from the engine and taking them out through the exhaust pipe.
An important piece of this system, the catalytic converter, works to transform some of these gases into water and carbon dioxide, but if this piece is having issues, you could fail the emissions test.
#6. Faulty sensors.
A faulty sensor can end up triggering your “check engine” light, resulting in a failed test. These could be a faulty oxygen sensor or mass airflow sensor that are bad or faulty.
#7. System issues.
There could also be a number of other issues that will cause a failed inspection. If there are issues with your ignition system, fuel injection system, or air injection system, it could end up resulting in a failed inspection.
#8. Other issues.
There are also a variety of issues that could result in a failed inspection, including a loose, cracked, or ill-fitting gas cap, waiting too long between oil changes, or not replacing your engine’s air filter.
In addition to these possibilities, there could be a number of other reasons your vehicle fails an emissions inspection. To understand the requirements for passing the test, review your state’s emissions testing guidelines.
How Do I Fix My Emission Failures?
If your car has failed an emission test or you are concerned about fixing an emission failure, stay tuned. In the next few paragraphs, we will explain how to fix failures on emissions tests.
#1. Check wheel tires.
Some things to check include safety tests. Check things like tires to make sure they are not punctured and have good tread life.
Fix the headlamps and put them back into good working order. Anybody can check the light – you don’t need a mechanic to check it.
#2. Change engine oil.
Since you can’t tell what’s coming out of the tailpipe, take a few preventive measures to ensure it passes the emissions test.
In older cars manufactured before 1996, the air exiting the exhaust tailpipe is measured with a dynamometer. So, you need to put everything in good working order to ensure the air coming out of the tailpipe is very low in pollutants.
That said, make sure the oil is clean. Change the engine oil and oil filter before the inspection, because if the oil gets dirty, the PCV valve will suck dirty vapors, burn them, and pollute more.
#3. Clean/replace the air filter.
Keep it clean; a dirty one can block airflow, causing the car to run lean and pollute too much.
#4. Check the Spark Plugs.
Ensure they are in good shape. Spark plugs have a gap between the electrodes and the body. If the gap is too wide, they won’t ignite as they normally would. Even if the car is running okay, if the gap is too much, it’ll pollute more and fail the test.
#5. Check the cooling system.
A low coolant level will make the engine run hotter and, of course, result in overheating. So make sure there’s enough coolant and that the engine isn’t overheating.
Put the cooling fan into a nice, smooth-running state. Start the vehicle and turn on the AC to check whether the fan runs smoothly.
Because the test takes place on a dynamometer, the car isn’t moving; if the cooling fans aren’t running properly, the engine will run harder, and your car will fail the test. A dynamometer is a measuring device used for determining torque or power.
For Instance, it is used to calculate the power generated by a motor, engine, or other rotating prime movers by simultaneously measuring force (torque) and rotational speed (rpm).
Older vehicles that were produced before 1996 are not equipped with an OBD11 plug-in socket. For this reason, CERTs do not test the engine with any computer other than a dynamometer.
#6. Fix engine check light.
If your car was manufactured from 1996 onwards, the test will not be performed on a dynamometer. They will plug a computer into the car to see if there’s a problem.
So, if the car’s check engine light is illuminated on the dashboard, get a certified mechanic to diagnose and fix the fault before you go for the test. If there’s a trouble code stored in the computer, the scan tool will detect it.
There are over 2,000 separate fault codes that can exist in a car. This makes it difficult to determine the cause of the illuminated light without a scan tool.
#7. Use fuel injector cleaner.
If you have tried everything mentioned above and the car still fails an emission test, you can try a fuel injector cleaner and pour it into the gas tank.
I recommend using a shop-line solvent. Pour a gallon of the solvent into a half-gallon tank and drive the car on the highway at maximum speed. Drive for about 30-45 minutes.
I have done this on several cars and have gotten them to pass emissions tests. Of course, this is not magic; if your car has faults, you need to fix them.
But if the car runs okay, this will help it pass the test because the solvent burns cleanly and pushes out cleaner smoke. If you have older cars with catalytic converter issues, this will help them pass the test.
What vehicles require emissions Inspection?
In an effort to reduce air pollution, the Federal Clean Air Act was amended in 1990. In response to the revised legislation.
The Environmental Protection Agency (EPA) designed a set of emissions standards that could minimize the volume of hazardous pollutants expelled by motor vehicles.
As a result, many states in the US adopted testing requirements and protocols for vehicles registered there.
Today, approximately thirty states require some level of emissions testing by law in order to register a vehicle. The degree of testing varies by state, and in some cases, by county.
While some states do not require emissions testing at all, the states that do offer certain exemptions from testing.
For instance, any vehicle that does not produce greenhouse gases – including fully electric cars and hydrogen fuel cell cars – do not need to be tested. Brand new vehicles are often exempt. So might very old vehicles. Again, it depends on your jurisdiction.
Check with your local DMV to determine if your vehicle needs to undergo an emissions test.
What If You Fail the Emission Inspection Again?
If your car doesn’t pass a second time, don’t panic. You still have options:
- Economic Hardship Waivers: If repairs are too costly, you might qualify for a hardship waiver. This keeps you driving for a set time, even with a failed test. You’ll need to prove you can’t afford the fixes. This often means showing your income and bills.
- Repair Cost Limits: Many places cap the amount you must spend on emission repairs. If you’ve spent more than this limit trying to pass, you might get a waiver. Keep all your repair receipts as proof. The limit varies by state, so check your local rules.
- State Regulations: Rules for waivers and extensions differ by location. Your local DMV is the best source for accurate info. Some states offer more repair time or special programs for older cars. It’s worth contacting them to learn about your options.
FAQs.
Q: What happens if I fail the emission test twice?
If your baby ride fails an emissions test, it means its emissions exceed the permissible levels for the manufacturing year.
When a vehicle fails the emission test, it is expected to be repaired and returned for another test within 60 days of the initial test.
Now, what happens if you fail an emission inspection 3 times or twice? You may qualify for a cost waiver if you meet the expenditure criteria and the repair is performed by a certified emission technician (CERT).
Q: Should I buy a car that fails the emission test?
In most parts of the United States, it’s illegal to sell a car that doesn’t pass the current emission test.
If a car you intend to buy has multiple failed emission test records or doesn’t have current records for up to a year, insist the car go for an emission test or get another car.
Q: How much does it cost to fix emissions?
The cost to fix emission problems depends on the cause of the failure. However, if a faulty oxygen sensor or EVAP system is diagnosed as the culprit, the repair and diagnosis cost should be $100 to $200 per vehicle.
Q: How many miles do you have to drive to pass smog?
Remember that internal combustion engines run on fuel. Drive your car 10-15 miles before getting to the smog station.
This will allow the engine to warm up and ensure that the catalytic converter, motor oil, and coolant are at normal operating temperature. It’ll also help your car pass the emissions test.
One of the emission inspection standards requires a smog technician to check that the vehicle is at normal operating temperature before running the inspection. However, this is one of the prerequisites for passing the emission inspection, and you can do it with ease.
Q: How do I get a waiver for emissions?
There are three types of emission waivers. Here’s how you can get any of them;
Cost waiver: You are expected to meet the maximum expenditure prerequisites for emission repairs. The repairs must be done by certified emission repair technicians CERT.
Economic hardship: To obtain a hardship exemption waiver, you must submit documentation to DMV stating that your annual income is below the federal and state poverty levels.
You will also attest that you have no other income or assets to pay emission repair costs.
Functional diagnosis: There must be documented reasons for the failed emission, and the documentation must be from the manufacturer, not a dealer.
The letterhead must state the reasons why the car cannot pass or is failing the emission test.
Q: What happens if I buy a car that doesn’t pass smog?
If you purchase a used car that doesn’t have a current smog test record, the dealer is required by law to fix the car so it passes smog.
Q: Can I still drive with emission problems?
As long as it is only emission problems you are experiencing at the moment, you can still drive without worrying about safety. However, you should diagnose and fix the faults before they escalate into an expensive repair.
Final word
Emission tests help ensure that only worthy vehicles are driven on the road. This is to ensure that vehicles emit less pollution into the atmosphere, protecting the environment and its inhabitants.
Having known the reasons for emission inspections, if you fail an emission test, get it fixed for the benefit of the road users.
Now, you know the reasons for a failed emission inspection and how to fix it, contact your local mechanic to fix it or drive down to CERT for a professional fix.