Emissions Control

Oxygen Sensor

The oxygen sensor measures the level of oxygen in a vehicle’s exhaust gas produced by the engine in the combustion process. The power train Control Module (PCM) uses the information provided by the module to determine the correct air to fuel ratio for the engine. Located in the exhaust system, the sensor enables the engine timing and fuel injection to function efficiently, facilitating emissions control. A failing oxygen sensor negatively impacts emissions and performance. The following signs can indicate the need for auto repair in Keller, TX.

Check Engine Light

The check engine light illuminates when an oxygen sensor fails. As the light operates for a number of problems, it is important to receive a professional diagnosis. Failure of the oxygen sensor is a common problem with vehicles of higher mileage.

Rough Engine Idle

A bad oxygen sensor can cause a rough idle, misfiring and irregular idle. These signs occur due to the sensors assistance with engine timing, air to fuel ratio and combustion timing. As a result, the engine is unable to operate as it should. Import Car Center can provide the auto repair in Keller, TX that you require.

Poor Fuel Mileage

A bad oxygen sensor also causes poor fuel delivery and improper combustion in the engine; this is due to insufficient or an excess of fuel being delivered to the engine. In addition, you will note that your vehicle’s gas mileage is reduced, potentially significantly. If you are purchasing more fuel than is normal, even if the engine check light is not illuminating, have your vehicle checked by a professional.

Replacing the Sensor

Typically, the sensor will require replacement every 60,000 to 90,000 miles. Check your owner’s manual for the manufacturer’s recommendation. However, if problems displaying the above symptoms occur, a faulty sensor may be responsible. Schedule auto repair in Keller, TX with Import Car Center.

Failed EGR Valve

The exhaust gas recirculation valve (EGR valve) is another component of the automotive emission system. It is designed to recirculate exhaust gases back into the engine intake, producing the effect of reducing cylinder temperatures and exhaust emissions. When a problem with the EGR occurs, performance and emission problems will occur. Our ASE certified mechanics can take care of your vehicle’s emission problems with reliable auto repair in Keller, TX.

The Signs

A failed or failing EGR valve often first presents itself with poor engine performance. Reduced power, poor acceleration and reduced fuel efficiency are common signs. A rough idle and illumination of the check engine light is also a common symptom of EGR valve failure.

Determining the Failed Component

As you can see, the symptoms are very similar between a failed oxygen sensor and EGR valve. Only a thorough diagnostic provided by a ASE certified mechanic will reveal the correct faulty component. You can count on Import Car Center for an accurate diagnosis, superior service, and reliable auto repair in Keller, TX

PCV Valve

In the process of combustion, most gases are exhausted through the catalytic converter, which neutralizes most of them. However, a small amount of the gases ends up in the engine crankcase due to common pressure leakage. Without assistance, these gases could corrode the engine and accelerate its wear prematurely. The positive crankcase ventilation valve (PCV valve) prevents this problem from occurring. Its operation is simple, using the engine’s vacuum to pull the harmful gases out of the crankcase.

Furthermore, a loose, clogged or broken vacuum hose can cause the similar symptoms of a faulty PCV valve. Checking the vacuum line is always recommended. Without a properly functioning vacuum hose, the correct amount of fuel will not be delivered, resulting in performance issues due to inadequate fuel, or too much fuel being delivered to the engine. Import Car Center can provide the automotive services you require, including maintenance and auto repair in Keller, TX.

The Signs of PCV Valve Failure

  • Engine surges and potentially black smoke from the exhaust pipe
  • Increased internal engine pressure
  • Oil leaks
  • Sludge buildup inside the engine
  • Misfiring when at idle
  • Increased use of oil
  • Hard start of the engine
  • Rough idle
  • Overly lean air-fuel mixture
  • Illuminated check engine light
  • Poor fuel economy


While mileage is certainly one factor in PCV valve failure, poor engine and system maintenance are also a common cause. However, not all new models have a PCV valve.  Manufacturers typically recommend replacement every 20,000 to 50,000 miles. Many owners request replacement of the PCV valve during the annual service visit. The valves are inexpensive on many models, while others cost more. In addition, some models use a filter in conjunction with the valve. Replacement of the filter is recommended about every 30,000 miles. Contact Import Car Center today to schedule auto repair in Keller, TX.

A bad PCV valve can be mistakenly identified as a failed sensor during diagnostics. For this reason, a visual inspection of the valve is recommended. When we provide auto repair in Keller, TX, after a comprehensive diagnostic has been completed, our mechanics will replace the bad valve, and your vehicle engine will run smoothly, and efficiently.

Import Car Center will provide superior service, excellent customer service for you and your vehicle. We offer a wide range of services, including battery conditioning for your hybrid or electric vehicle, and more. We have built our reputation with the goal of being the best in the business.

Furthermore, we firmly believe a business should be built on the practice of integrity, which results in repeat customers who are confident in our services. Give us a call today to schedule your vehicles annual service or other maintenance, and professional auto repair in Keller, TX.

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