I am having the same issue as a few others have posted on here except with a different code.

Misfires under load. Tune up, fuel filter, and fuel pump have been done. This issue seems to happen more in warmer weather.

Misfire shows everytime and MAF sensor shows on occasion. I think it is really happening each time, but by the time I get it checked out the MAF code is gone.

Any insight to why the MAF code also is getting triggered? I should also mention that I got a Oreilly distributor cap when I did the tune up. Put it on and the car ran great for the first day. The next day it started missing like crazy. Put the old cap back on and it runs ok, but I still get the misfires under load.