Rough Idle Due to Faulty EGR Switching Valve on Hyundai Sonata

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: 113,238 (5,400–320,000)
Engines affected: 2.0L 4 Cylinder, 2.4L 4 Cylinder, 2.5L V6, 2.7L V6, 3.0L V6, 3.3L V6
15 model years affected: 1998, 1999, 2000, 2001, more2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011, 2013, 2014
128 people reported this problem
Viewing 1 - 20 of 38 comments
engine idles rough when in drive but not in neutral
Rough idle when stopped. Car shakes a lot.
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????
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.
Rough idle, lack of acceleration at times, and poor gas mileage.
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.
My 2004 Hyundai Sonata 2.7 V6 started having a rough, low rpm idle after it hit 105,000 miles. I haven't had it repaired yet but plan to do the work myself. Thanks cor the helpful information, much appreciated!
Rough and unstable engine. Feels like gas is choked from engine or loose battery wires. Then car takes off. Scary! Not fixed yet
Car started shaking a lot when parked and engine was at idle. Check engine light is on and car shakes when in stopped in Park or Drive, but not neutral.
Roough idle, jerks a little when driving, began to stall. Will change Throttle Position Sensor and see what happens.
My sonata dies when I slow down at red lights and when I slow down to make a turn.
Car vibrates. Changed EGR solenoid valve. Still vibrates, check engine light still on, OBD II still reads exhaust gas recirculation low.
Check engine light, rpm fluctuations, shakes at stoplights. Also, has stalled when getting gas.
Rough idle in drive
When car is idle on stop, rattling noise. But on neutral or drive sound dissipates.
when a/c in on the engine almost dies when in gear
Car idles out and dies when stopped
Check engine light came on the first time when we were up at elevation. From there the engine (at different times) seemed to idle a little rough and get worse gas mileage.
car vibrates severely while idling in gear...but smooths out while in gear or neutral
2004 kia optima 4 cyl 2.4
Failed emissions due to egr