Honda civic 99 EX with engine light. I had the car diagnose and was told the problem was originated by the Iddle air control valve. After placing in the new IAC the problem still persist. The car iddles and hesitates to take off.
I had a second opinion from another mechanic and was told it could be a Vaccum leak or an O2 sensor. What the hell could it be? it's very frustrating and as a last resort was wondering if anyone had this problem before.

 

It could be a Vaccum leak or an O2 sensor

check everything and make shure it all loks to be in order as well as no unhooked vaccum hoses