What is manifold pressure?

[Wahooka]

The lesson tutorials are suddenly asking me to change the manifold pressure.

It was never explained in any of the previous tutorials, suddenly they are asking me to do it.

What is this all about?

Thanks for the help.

[shadowgravy]

Manifold pressure is basically the available power being produced by your aircraft's engine.

https://pilotinstitute.com/what-is-manifold-pressure/

https://www.quora.com/Why-can-we-fly-C172-without-a-manifold-pressure-gauge

Without knowing what aircraft you're flying or the particular tutorial lesson, it's difficult to fully answer your question. If you're in the C172, about all you can do is is increase/decrease your throttle or adjust your mixture for altitude. Changing manifold pressure is easier to understand with aircraft that have adjustable RPM, and you want to, say, cruise at 2100 RPM. Your throttle input and mixture setting will then affect your manifold pressure guage's reading. The aircraft's operating handbook would usually have a chart or table showing the optimal manifold pressure for a desired speed, altitude, and fuel consumption.

[Wahooka]

Thanks, the lessons are asking you to change your manifold pressure instantly, so I assume they just mean to adjust the throttle, because I don't know how to change the pressure that quickly.