All I can say is "when it rains, it pours".
I've been trying to figure out a mysterious lean condition on my wife's Ford pickup. I had the computer read when the "service engine soon" light appeared. It showed that it had a lean misfire on both cylinder banks. That would normally mean a bad mass airflow sensor, so I replaced that ($100 US) and the airfilter ($15 US). Disconnected the battery to reset the computer. The light stayed out for about 1 day, then came back in all its glory. Next was the fuel filter (about $100 US), done at a local garage as I don't have the line tool to replace it. Then I replaced the spark plugs too ($18 US). So far I've spent over 200 bucks, and the damn light is still on. The truck runs fine, gets decent fuel mileage, and is driving me crazy! The only other thing that could be wrong is both oxygen sensors went bad at the same time, or the computer has a glitch. I told her it's going to have to wait until after the holidays, then we'll start again. Cars (and trucks) suck!