Need to check with the manager of the place. Down in tucson its just push it and let go no need to hold so a quick throttle blip is basically it.
All they are looking for is SMOKE and nothing else. They get all the readings they need off the computer and from the tail pipe probe. Mine has 11% or less on the test but it does not get run a lot either so I have to take it out on a run 1st. R floor it and then let it off. Ask to see the procedure they are to follow, but since you ar eup in east LA there is no telling what is going on.