like the title says I've got a surging idle that wasn't there before the manual swap. right now the car is running a manual P28 ecu and the only code is 21 for the Vtec solenoid which it doesn't have cause it's a d15b7. I read other posts saying it could be the iacv and/or the fitv so I took off the air intake and covered the two holes in the throttle body. when i covered the fitv hole idle stayed the same, but when I covered the iacv my idle steadied and stayed at 700-800 rpm. I'm not sure what exactly this means. should I try cleaning out or replacing my iacv? any help appreciated

 

I converted the original p06 ECU from auto to manual and the idle seems smoother but it still idles rough if I drive around a minute or give it some gas. it also likes to idle a little high, around 1100 rpms most of the time instead of 750+/-50rpms. Should I still be looking to change my IACV and/or FITV? I could really use some help with this

 

figured it out, changed out the IACV and it idles just fine now