Kia rio 2004 engine running problem

P1166 code keeps coming back even after new fuel pump, coil packs, o2 front sensor, ck’d all grounds to ecm, ck’d for vac leaks. Still have same code. Engine runs rough at idle and lack of power as soon as ck eng light comes on. Any help is greatly appreciated

This link suggests a problem with the idle air control valve.

Thanks for the info. I’ll be checking all items tomorrow. Will let you know

The link re: the idle air control valve worked! the valve was stuck & I was able to clean it, reinstall & that fixed the running problem. This was totally the problem & believe me - I spent alot of time on the car - and would never have believed that your suggestion was the answer. Thank you so much. harleychuck

Glad to hear the info helped you out. Thanks for the feedback and you’re welcome for the help.