Hi
I have a 97 imprezza outback with a high idle speed (over 1100 rpm) most of the time. cables were already checked and they seem to be working fine. Any thoughts? Thanks

When you say idle speed, do you mean the engine rpm when the car is in neutral?
Is the engine warn when it's running at 1100 rpm or is the engine cold?
Checked the engines oil temp gauge?

Or maybe if the idle control valve is sticking? It's a little cylinder next to the throttle body opening held on by 2 screws with some wires going to it. You can just take it off and clean it.

And if none of the above, I'd bet on a vacuum leak. You can check for that by getting a can of carb cleaner or starter fluid and spraying it around the engine. If you find a spot with a leak, it will suck it in and you'll hear the engine change RPM.