Open and Close Loop Mode

[koya1893]

I probably did not tittled that correctly, but I would like someone smarter than I clarify the the difference between aN "Open Loop and a Close loop" as it relates to the O2. I am having a senior moment here, some help is appreciated. thank you.

[myoldyourgold]

OPEN LOOP - this is the mode your ECU is in until the coolant temperature and a couple other sensors get to operating values. This is also true when you are at WOT or when throwing codes/ CEL's

CLOSED LOOP - the ecu uses information primarily from the Oxygen Sensor and adjusts fuel delivery and timing to achieve minimum emmisions, better gas mileage and power.

[koya1893]

Thank you. I went back and re-read some data, you verified my initial conclusion from my notes from way back except my notes was simplified to: Warm Up and Oporational Temp.