Need Help P0507 Engine Idle Higher than Expected

[ctrobk]

I could use some help/advice on an intermittent CEL for P0507, engine idle higher than expected.

Background: 2015 XC60 Drive E T5 FWD with 2.0 turbo, 57k miles. I recently experienced erratic engine idle. Once the vehicle was at normal operating temp, the engine would surge while stopped or in park. In addition I had the awful squeal that sounded like a belt. After some troubleshooting and internet searches, I traced the issue to the oil trap. My proof was removing the oil filler cap while the engine was squealing, I could feel the vacuum when removing the cap and the squealing went away.

I purchased the oil trap from my local dealer at a cost of $240. Swapping the trap out on the 2.0 is relatively easy. It sits on top of the engine and minimal items needing to be removed to make the repair. I think it took me less than a half hour to swap it out. The new trap solved 99% of my issues. I still have idle fluctuation from time to time and it will cause the CEL to come on. I suspect there is an additional component that needed to be replaced or cleaned when I did the trap. Maybe a hose or valve?

Does anyone have any input on what else I should be looking for?

Unfortunately not a lot of info on these 2.0 motors on the forums and internet.

Thanks in advance for help.