Had a check engine light which gave out a code p0505. I checked the IAC valve which looked worn and replaced it with a new one. Now when I start the car it starts at a high idle (around 1.5k to 2.5k) before going down to around 1250 rpm and after about a minute it sounds like it’s doing short revs. Also when I’m around parking lot speeds the car starts jerking back and forth.

Most google searches lead me to believe there’s a vacuum leak however after doing the carb cleaner test I can’t seem to find any. The engine light also didn’t go away.

 

A few of things come to mind:
- check the connectors are fully mated. The IACV connector is tucked under on the lower left of the TB. I had a code when I forgot to connect it.
- disconnect the connectors and spray them with electronic cleaner. Allow them to dry before reconnecting.
- check and follow the small hoses above the TB to each end

 

Have you done an idle relearn process?
a quick google search turned this up, second post:
https://www.crvownersclub.com/thread...cedure.124522/