Top 6 Reasons Why your Car Failed the Smog Check

You need to know that in California, there is no way that you can register your car if it doesn’t clear a smog check in Rancho Cucamonga and other locations every two years. Unless your car does not need a smog check, it’s your responsibility to get a passing grade.  

From a smog test center, you not only can figure out why your car didn’t clear a smog check; but they can also fix it and retest it. In this article, we’ve identified the common reasons why cars fail smog checks. 

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2. Untidy Air Filter 

When your air filter is dirty, the combustion chamber cannot get sufficient air. So, you will have an excessive amount of carbon discharged in your exhaust. This will lead to a situation where your automobile will fail the smog check in any of the authorized smog test centers in California. Generally, replacing the air filter will solve the problem.  

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3. Poor Spark Plugs 

Poor and worn spark plugs will cause your engine to misfire. This misfiring may compel your vehicle to fail the smog check miserably. You must have a fully operating ignition system in order so that your car can pass the test. If the spark plugs are of inferior quality, then you may end up with a failing grade.  

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4. Poor O2 Sensor 

Whenever your oxygen sensor is poor, your vehicle may not clear the smog test as it is discharging excessive carbon in the exhaust. The O2 sensor reports the oxygen levels in the exhaust. When the data is inaccurate, the engine control module may put excessive fuel in the combustion chamber. 

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5. Damaged Catalytic Converter 

You won’t clear a smog check when the catalytic converter turns out to be a faulty one. Other symptoms that the catalytic converter is going haywire include rotten egg odors and an overheating engine. You must get the catalytic converter replaced right away during smog service in Rancho Cucamonga or elsewhere because this will be the exhaust part that is dealing with carbon monoxide. 

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6. Rich Fuel Mixture 

It has been observed that a malfunctioning O2 sensor, malfunctioning fuel pump, malfunctioning mass airflow sensor, or leaking fuel injectors can form a rich fuel mixture inside the combustion chamber. So, excess gas is being burned away and as a result, there are surplus carbons inside your exhaust. The unwanted carbons will lead to the failure of your vehicle during the smog check. 

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7. Faulty EVAP 

The evaporated emission control system or EVAP stores your gasoline vapors inside the tank. When there is any issue with this system, or with the vacuum hoses, purge valves, or vents, you will fail the smog check. A loose gas cap may also lead to your vehicle’s failure of the smog check. 

Conclusion 

If possible, avail yourself of the free check engine light diagnosis, so that your car never fails the smog test. If there’s any problem, then fix the problem, and retest it.   

Top 7 Reasons Why Cars Fail a Smog Check

As a vehicle owner, you must know that you can’t register your vehicle in California if it fails to pass a smog check every two years. Unless your car does not need a smog check, you need to avail yourself of a passing grade.  

Most smog test centers in California cannot just probe and find out why your car didn’t clear a smog check, but they can also fix it and retest it. The most common reasons why vehicles fail smog checks are as follows- 

1. 
   

2. 1. Bad Spark Plugs 

Bad and worn spark plugs will surely compel your engine to misfire. Due to this misfiring, you might find that your vehicle fails to pass the smog check. You must have a fully operating ignition system for your car to pass the test. When the spark plugs are in poor condition, you might end up with a failing grade.  

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3. 2. Poor O2 Sensor 

When your oxygen sensor is poor, then your car may not clear the smog test as it is discharging an excessive amount of carbon in the exhaust. The O2 sensor reports the oxygen levels in the exhaust. If the data is inaccurate, the engine control module may put an excessive amount of fuel inside the combustion chamber. 

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4. 4. Defective Catalytic Converter 

It's next to impossible to pass a smog check if you have a defective catalytic converter. Other indications that the catalytic converter is going haywire include rotten egg odors and an overheating engine. You must have to replace the catalytic converter right away, as this is the exhaust part that deals with carbon monoxide.  

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5. 5. Dirty Air Filter 

When your air filter is dirty, the combustion chamber will not get sufficient air. So, you will have excessive carbon being discharged in your exhaust leading to your automobile failing the smog check in Rancho Cucamonga or other locations. Replacing the air filter ideally resolves the issue. 

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6. 6. Rich Fuel Mixture 

A defective O2 sensor, malfunctioning mass airflow sensor, faulty fuel pump, or leaking fuel injectors can form a rich fuel mixture in the combustion chamber. So, excess gas gets burned away and as a result, there are excess carbons. These excess carbons will lead to your car’s failure of the smog check. 

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7. 7.Ignoring Check Engine Light Diagnosis 

Usually, a free check engine light diagnosis is nothing more than hooking your vehicle up to a machine to scan for trouble codes in your car’s computer system. Then you receive a printout that explains the meaning of each code. Though merely pulling the codes isn’t a proper diagnosis, it’s better not to ignore the same.   

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8. 8. Faulty EVAP 

The evaporated emission control system or EVAP preserves your gasoline vapors in the tank. When there is any issue with this system, or with the purge valves, vacuum hoses, or vents, you will fail the smog check. A loose gas cap may also lead to your failure during the smog check. 

Conclusion 

Find out the best providers of smog service in Rancho Cucamonga to ensure that your car never fails the smog test. If there’s any problem detected, then fix the same, and retest it.