[Thurazor]

I'm not actually sure if a bad 02 will trigger the check engine light. The MAS can trigger the check engine light, but it's only when it's unplugged or in very tough shape. Plus, if your MAS was in tough shape you should have also noticed a lot of hesitation with accelaration and stalling. If you get a multimeter, there are tests you can do on the 02 sensors. You can get one at Radio Shack for $20 with the battery, and you'll need a service manual to find the diagnostic numbers, or just find someone else on the board who can give them to you.