I just recently put on my type 1 racing race headers with a cell defouler back on my 2010 Honda fit and decided to swap my spark plugs out for denso iridium ik20s while I was back there. After the change my idle is very lopey at times but it corrects itself it'll drop from 800 to 500 then compensate and shoot up to 1100 and when I try to accelerate it almost dies in revs I have to mash the gas hard so it "wakes" up then I go do you guys think this is an o2sensor or Afr sensor? I feel like I lost power rather than gaining it Your educated advice is greatly appreciated

 

I'd look for an exhaust leak or vac leak first