Go to this link: http://www.2carpros.com/articles/engine-misfires-or-runs-rough

1.Defective spark plugs
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
10.Throttle position sensor.
11.Manifold absolute pressure sensor
12.Mass Airflow Sensor
13.Idle air control valve

Note: If it doesn't apply disregard it-

Answered by rasmataz
68 questions asked

Thank you. We did number 13 and think we'll do the plugs and wires. I wish I could know for sure:( Thanks

Response from crone
2 questions asked

If there were a major problem, would it pass emissions, and wouldn't it run rough throughout driving? This is only idle and coming from idle just today...it's not always, either. AC makes it worse.

Response from crone
2 questions asked

I'v decided it's all messed up. Changed plugs and wires and now engine light is on with a high idle the codes are:
P0122
P1505
P1507
Changed IAC before plugs still not right. When driving around the block, the trans doesn't engage it's like revving super high before it might engage at least 3000 right now it idles at 1500 and fluctuates to 1800. This is aggravating especially because I wanted a sonata. It's' 2002....any suggestions. I know what the codes mean, but that isn't helpful when I have no clue what they're talking about. Already did timing belt change and cannot afford more money! UGH

Response from crone
2 questions asked