I have a 2002 Civic EX sedan. Today the engine started surging, it started to idle around 2000 rpms drop to 1200 and back up to 2000 and over and over again. Two MIl codes pulled are P0505 (idle control malfunction) and P1505 (PCV leak) I assumed perhaps the pvc was bad or the rubber line cracked I climbed under the car pulled off the rubber line to the PCV and put my thumb over it. It had a strong vacuum but the engine was still surging. Does anyone have any ideas where to look next? I don’t see any visable issues, and I do not hear any vacuum leaks.
You haven’t checked the IAC valve yet. You only looked for a PCV problem.
Check the Idle Air Control valve and all associated circuits.