Increased idle speed

I recently had a front emission sensor replaced and since then the idle speed has increased slightly,should I be concerned?

How much is slightly? Can you hook up a device to read the actual RPMs? I believe it should be around 900 in neutral and 600 in drive.

I have mine tuned for 800 in neutral and 650 in drive.

This can be caused by a sticking IAC valve, among other bad sensor data.