At idle for the last few months, my boost gauge shows around -7 and not -10. I've done exhaustive vacuum leak searces and can't find any. Idle quality is fine. IAC counts or position is active when it is doing this. It will sit at -10 when coasting. Is this an IAC problem?

No, this is a colder denser air issue with a small pulley. When it warms up, the problem will magically fix itself.

same issue when it gets cold....

Read above post...not an issue.

We all notice it, exhaust ourselves searching for it and then accept the fact that with a smaller pulley and denser air.. you are simply pushing a little positive pressure toward the intake and reducing the overall vacuum from -10+ to ~-7psi.

My 2" pulley outflows my bypass at idle in the heat of summer now. Not just winter. Same effect in the long run though.

John, you have the 2.5" on the car right now, right?

It was still warm out when this started, and it does not go away when it'* warmed up.

2.5"

Get on the highway..let off the gas. What'* it at?

There you go..it'* fine. John..you described what I see everyday. The only other thing we can tell you is .. "vacuum leak" and you've exhausted that possibility.