The tube from the air filter to the intake can develop cracks, fixable with
duct tape.  If you can, remove the tube from the engine compartment and
check the entire length and circumference.

MAF stands for Mass Air Flow.  The leaks generally occur between the air
flow meter and intake plenum.

I don't remember which type of air flow meter you have.  Earlier ones were a
hinged flap attached to a potentiometer.  As air flow increased, the flap
was opened more, and the more the flap opened, the more voltage was sent to
the Electronic Control Unit.  On this type, make sure the flap moves
smoothly.

Some air flow meters were basically a small mirror mounted on a wire that
was stretched across an opening.  An LED light was projected on the mirror
and as more and more air flowed past the mirror, it would oscillate more
quickly and the sensor picking up the reflection from the LED would know how
much air was going past the meter.

Yet another type is a hot wire.  A wire's resistance changes with
temperature, and as more air flows past the wire, it is cooled, changing its
resistance.  The meter measures the varying volage from the varying
resistance.

I didn't notice the leaks until I took it off and flexed it a little bit.
Then I found a bunch, in between the 'flutes'. I patched them with Duct
tape.

The air filter is in it's little home, OK? Now right after the airbox you
will see a gadget that has a Toy P/N with a connector going to it. That's
the Mass Air Flow sensor. It meters the air from the filter to the engine,
through the tube. That's why, if there is a leak in the tube the engine
runs rough, because the engine is getting more air than the MAF is telling
the computer.