2010 Prius still shakes after head gasket job and EGR + intake cleaning

There is no direct egr step position status or feedback. But the egr step test uses the map pressure as a good indicator.

A lot of this assumes your previous egr block test was successful. I would block the flow manually again and drive it 15 minutes in normal mode (not maintenance mode) and verify the engine runs good with a full warmup. If it does not continue to run smooth you have to reevaluate your focus.

Egr step test with Techstream

Run the egr step test procedure while watching the map pressure. The engine must be placed in maintenance mode to force continuous running. The procedure wants you to warm up the engine. You will see map pressures at idle changing as you command the egr open using Techstream.

When the egr is closed at step 0, the map pressure usually reads about 4 psi absolute. As the egr step opens the psi will increase causing idle roughness around step 15-20.

You will later be able to watch the map pressure under normal conditions and significantly understand what the egr is doing. You have to understand the egr should be closed at idle and low rpms. The egr valve is also closed at wide open throttle.