Well, I did search, but it seemed like I couldn't find what I was looking for...

I think I may have answered my own question? The duty cycle will show 85 until the car is at operating temp...then the system goes into closed loop and begins using the o2 sensor for correction? I suppose it's possible that the car wasn't FULLY up to operating temp when I performed the test...

And as for the diag codes...I pressed the button on the diag box by the battery, held for 2-4 seconds and watched the blinking LED, it blinked 4 times, held it again for 2-4 secs, and it blinked once. Now the LED light is on at all times...does that mean I'm in diagnostic mode, and the duty cycle can now be read?

Also, how exactly do I test on/off ratio? Can I use my DMM for that? Or do I need to build the special tool with an LED that I have read about?