10 year old quantaray pz-1 flash compatible with canon rebel xti camera?

Answer 1

Probably not. Check with your local camera store.

You'll be much better off getting the Canon flash designed for your camera. Since your camera has E-TTL off-sensor flash metering you'll want a flash that is compatible. Buy the top of the line flash offered for this camera*. Buy the off-camera flash bracket with it.

* In my experience its always better to have a feature and not need it than to need it and not have it. You know - like side curtain air bags.