Car Problem Reports

Hyundai Sonata Rough Idle Due to Faulty EGR Switching Valve

Hyundai Sonata Problem
45 Reports
Me Too

Model Years Affected: 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2010

Engines Affected: 2.4L 4 Cylinder, 2.5L V6, 2.7L V6, 3.3L V6

Average Mileage: 108,074 mi (16,000 mi - 200,000 mi)


On the 2.7L V6 and 2.4L 4 Cylinder, a defective exhaust gas recirculation (EGR) switching valve may cause an intermittent rough or unstable idle engine.

  • rmkjmk, , 2.4L 4 Cylinder, 93,560 mi

    engine idles rough when in drive but not in neutral

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  • Visitor, , 2.4L 4 Cylinder, 37,000 mi

    Rough idle when stopped. Car shakes a lot.

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  • Visitor, , 2.4L 4 Cylinder, 110,000 mi

    Rough idle, lack of acceleration at times, and poor gas mileage.

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  • revroysail, , 2.4L 4 Cylinder, 67,000 mi

    engine light indicated need to repalce EGR valve. Did so a a week later it says the same thing again and idle is rough again. Why????

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  • Visitor, , 2.4L 4 Cylinder, 150,000 mi

    Rough idle and engine seems very rough while accelerating from a dead stop. Runs well at cruising speed. Only seem rough when the engine is under load.

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  • Visitor, , 2.4L 4 Cylinder, 45,600 mi

    Rough and unstable engine. Feels like gas is choked from engine or loose battery wires. Then car takes off. Scary! Not fixed yet

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  • pbc90723, , 2.4L 4 Cylinder, 80,000 mi

    Roough idle, jerks a little when driving, began to stall. Will change Throttle Position Sensor and see what happens.

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  • Visitor, , 2.4L 4 Cylinder

    Failed emissions due to egr

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  • Visitor, , 2.4L 4 Cylinder, 116,000 mi

    She runs ruff when idleing and even worse if the a/c is running . The shaking slows down if i put her in drive or neutral.

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  •  Rookie

    Just bought one for my Daughter - original owner had it before me, did all the required maint. 190,000 miles and looks and drives great! The problem was the check engine light. The issue was the MAF (Mass Airflow Sensor). Get the special spray at your local auto parts store for the MAF. Take it out and clean it, and change the Air Filter at the same time. Then disconnect the battery for at least 3 hours to reset the check engine light. Drive it for at least 100 miles - I had to do this to reset the computer to pass emmisions. It is still running like a champ. It was so good, I cleaned my 2009 Camry and 2001 Sequoia's MAF. I hear this helps with gas mileage too. A Throttle Body clean wouldn't hurt either.

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