2001 Hyundai Sonata Idles Rough/Shuts Off Intermittently

DJCEPHEUS

MEMBER
2001 HYUNDAI SONATA
4 CYL
FWD
AUTOMATIC
112,665 MILES

Hi! My 2001 Hyundai Sonata has been idling rough/shutting off intermittently for the last 6-8 months, with the "Check Engine" light coming on only about 2-3 months ago. I have tried cleaning the fuel lines, replacing the IAC motor, and, today, replacing the MAF sensor. It seemed like the problem was fixed after changing the sensor, but it started to idle rough again. (The car will idle @ about 800-1000 RPMs, drop down to about 400-600 and then shoot back up again. Occasionally, after driving for long distances and coming to a stop @ a light, the car will just shut off).

I took the car to my local service station to see why the "Check Engine" light was still on, but there were no pending codes. (The light is off now.) Since this morning, I have changed my air filter and tightened the air ducts, but the car is still idling roughly every so often. What am I missing here? Please help! I can't keep dropping money on parts that are not fixing the problem.

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Have it checked for vacuum leak and test the PCV and EGR valves-

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Wednesday, August 20th, 2008 AT 5:42 PM

DJCEPHEUS

MEMBER
2 POSTS

One thing to add.

My "Check Engine" light just came back on. While there were no pending codes related to MAF sensor, another code came up, Code PO122, which is "Throttle Position Circuit Too Low." Would this have an effect on the way the car idles?

Thanks very much for the initial answer to my question! :)