The o-ring is the rubber seal between the MAF and the air hose.
If you unhooked the MAF, you caused the ECU to run in open loop, that is whay it didn't stall, it also runs full rich when not connected.
With that 1884 code, you would be better off going to see your mechanic.

 

whered you get the new mass air?

 

Replaced CkPS. P1884 gone after driving it for 20 miles. CEL back on with P0101 and P0103. Now back to the MAF sensor correct? I replaced the sensor not the entire unit. Could that be it?

Any info would be much appreciated. Thank you.