Truck is surging up and down at idle?

These could be a few things, so we need to start with this guide to help get on the same page as to the possibilities and solutions.

https://www.2carpros.com/articles/engine-surges

If the MAF is okay, then we need to move onto a possible vacuum leak. So that means we need to run through this guide and see what turns up:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Lastly, we should check for codes and find out if we have anything to point us in the right direction.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Lastly, I want to make sure we run through this guide to check the MAF because if we didn't check it the correct way, it could still be the issue.

Did you unplug it and the engine not smooth out? If that is how you checked it then that is not definitive, so we need to run through this and see what turns up.

https://www.2carpros.com/articles/how-a-mass-air-flow-sensor-works-maf

Thanks