Why so many pending faults?

[Alansd]

My wife was driving the 2006 when the limp home mode happened. Of course it freaked her out. She shut it off, waited a few, and then it started and got her home just fine.
No check engine light ever came on. I ran the diagnostic tool and got no faults recorded.
But, there are 4 pending faults. Not sure what that means totally-

P0306
p100
p0621
p0421

Two are mass air related, one is cat related, one I have no clue on, somehting about a generator Lamp?

Why so many pending faults and what should I do next? Thinking of cleaning the mass air sensor first. This Expy had new plugs and a couple of coils about 12000 miles ago. Has not has the trans serviced since I got it a year ago. Did have a fuel sensor changed also right after the plugs.

 

[stamp11127]

That isn't that bad, just a few codes.

Clean the MAF with the correct cleaner, check the connector while you are there, should be secure.

The code about the generator will depend on your trouble shooting ability, electrical/electronic tools available (dmm) and your desire to fix it yourself or have others do it for you.

 

[Alansd]

wonder why it went to limp mode? It was sitting a few weeks and the battery went down, but has been driven some in the two days since..Scary