Also the previous owner installed a AEM intake but one plug that joins the harness of the maf, is unplugged what is this plug for? I ask because the car is idling kinda rough.
If it is a hose that is unplugged, why not just plug it back in?
If it a hose port that looks like its missing a hose, skim through this post:https://www.celicahobby.com/forums/ubbthreads.php/topics/446753/what-is-this-hose.html
That particular hose port on your throttle may be intentional and should just be capped with a rubber Hood
Also have a quick read through this link:https://celicahobby.com/forums/...r-intake-need-help-with-vacuum-hose.html
Finally, if your care is running rough, have you take it in for a tune-up lately? Had the sparks and timing checked? have you looked at the oil to inspect for any deposits left within it?