2018 Kia Rio Has A Check Engine Light

Resolve Check Engine Light Issues in Your 2018 Kia Rio

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Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
40% chance it's the
Emissions System
0%
60% chance it's
Something else
The most common reasons a 2018 Kia Rio has a check engine light are an emissions system component, a sensor, or a catalytic converter.
  • Emissions System: A faulty emissions system component, such as an oxygen sensor or EGR valve, can lead to increased emissions and trigger the check engine light.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2018 Kia Rio has a check engine light?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

A faulty oxygen sensor is one of the most common causes of a check engine light. Symptoms may include a decrease in fuel mileage, hesitation or misfiring from the engine, rough idling or even stalling. A faulty sensor may cause the vehicle to fail an emissions test.

Any time there is an emissions fault the check engine light will be displayed. The purpose of the check engine light is to inform the driver that an emission related fault has been found, and that there are on-board diagnostic (OBD) trouble codes stored in the powertrain or engine control module. Additionally, since the emissions systems are so intertwined into engine control and transmission control systems, symptoms may include nearly any sort of drivability concerns. This may include harsh shifting, failure to shift, hesitation on acceleration, jerking, engine failure to start or run, loss of power, or any number of other drivability issues.

Due to the nature of electrical systems on modern vehicles, the range of problems these can cause are nearly limitless. However, there is a way to categorize them in two ways. Permanent and intermittent problems. Permanent problems appear and remain. This may be the vehicle will not start, the radio does not work, or the door chime will not turn off among many, many others. These problems are more straight-forward to diagnose since they present themselves at all time. This means there will always be a fault to find. Intermittent electrical problems, however, can be difficult or impossible to locate, since they appear then disappear without warning. The best case scenario for an intermittent issue is when replicating the problem is easily accomplished and understood. This allows a technician to make an issue semi-permanent, allowing them to find the fault. Other issues that come and go without warning and cannot be replicated on demand must occur when the technician is servicing the vehicle, otherwise there is no problem to correct. It is most important to understand that electrical system faults always require inspection, and can include the vehicle working in any manner, or not working at all.

Like we noted in the last section, general diagnosis symptoms are the most vague of the bunch. There are several diagnostic spectrums, electrical diagnosis, drivability diagnostics, engine diagnostics, transmission diagnostics, and the list could continue for about 5 or 10 more spectrums of diagnostics. The most important take-away here, is that general diagnostics are diagnostics that have no other spectrum in which they fit, or the problem is unknown. This means that any vehicle left outside of a repair facility with the keys and an authorization to perform diagnosis will be diagnosed under the general diagnosis spectrum.

When the Check Engine Light comes on, you may experience engine performance issues such as poor acceleration, rough idling, or an engine that won't start. In some cases, no abnormal symptoms will be experienced. Other systems like the transmission or ABS can cause the Check Engine Light to illuminate and lights for those systems can come on at the same time. Similar lights may say "Check Engine Soon", "Malfunction Indicator Light" or just "Check". In rare case the engine can overheat.

What are the first steps to diagnose the check engine light on a 2018 Kia Rio?

To effectively diagnose the check engine light on your 2018 Kia Rio, start with a thorough visual inspection of the vehicle. Begin by checking the gas cap; ensure it is securely tightened and free from damage, as a faulty gas cap is a common trigger for the check engine light. Next, utilize an OBD-II diagnostic scanner to connect to the vehicle's OBD port, which will allow you to retrieve specific error codes that can pinpoint the underlying issue. Pay attention to any additional symptoms your vehicle may exhibit, such as unusual noises or performance issues, as these can provide further clues. Additionally, consulting the owner's manual can offer insights into what the check engine light may signify and suggest troubleshooting steps tailored to your model. If these initial steps do not lead to a resolution, or if the problem appears to be more complex, seeking assistance from a qualified mechanic is advisable to ensure proper diagnosis and repair. By following this structured approach, you can effectively narrow down the cause of the check engine light and take informed steps toward resolving the issue.

What are the common problems that could cause the check engine light to illuminate in a 2018 Kia Rio?

When the check engine light comes on in a 2018 Kia Rio, it can be a source of concern for any DIY car owner. One of the most frequent culprits is a loose gas cap, which can disrupt the vehicle's evaporative emissions system. Another common issue is a faulty oxygen sensor, which not only affects fuel efficiency but can also increase harmful emissions. Additionally, problems with the catalytic converter can lead to significant performance issues, as this component is essential for reducing emissions. A malfunctioning mass airflow sensor can also trigger the light by disrupting the air-fuel mixture, resulting in poor engine performance. Furthermore, issues with spark plugs or ignition coils can cause engine misfires, while a faulty thermostat may lead to overheating. Lastly, problems with the EGR valve can impact both engine performance and emissions. Addressing these issues promptly is crucial to maintaining the vehicle's health, and while some problems may be straightforward to fix, others may require professional assistance for proper diagnosis and repair.

How urgent is it to address the check engine light in a 2018 Kia Rio?

Addressing the check engine light in your 2018 Kia Rio is not just a matter of convenience; it is crucial for maintaining the safety and reliability of your vehicle. Ignoring this warning can lead to serious consequences, including significant engine damage and costly repairs. The check engine light indicates that there may be an underlying issue with your engine or emissions system, which, if left unaddressed, could escalate into more severe problems. For DIY enthusiasts, utilizing the onboard diagnostics system can be a valuable first step in identifying the specific issue triggering the light. This proactive approach not only helps in diagnosing the problem but also prevents further damage that could compromise your vehicle's performance and fuel efficiency. Moreover, continuing to drive with the check engine light illuminated can negatively impact your car's emissions, contributing to environmental concerns. Therefore, it is essential to take immediate action when this warning appears, ensuring your Kia Rio remains in optimal condition and safe to drive.

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