The problem is that when I am braking to almost a dead stop and at a stop, the RPMs revs up a bit then goes back down and keeps on doing it until I drive again.. It went away for a bit after i seafoamed my car, but it's starting to come back. This happens pretty frequently now and I don't know why. Could it be because of my removed mid-muffler and resonator, or something else? Anyone else has this problem?

 

Sounds like your IACV. I had the same problem two years ago after not driving my car for about a month. Go for a nice spirited drive on the highway, make sure all the seafoam is burned out. If that doesn't work, you can try to clean out the valve. If not, you may have to replace it; I think I was quoted around $170 parts and labor from the dealer.

Are you throwing a CEL?

 

IACV. You can try to clean it first, but you'll most likely have to get a new one. I got one a couple months ago for around $125. Easy to install. Don't bother having the dealership install if for you.

 

Have a pic of the IACV?

No CEL here.