At 03:23 PM 1/24/2002 -0500, you wrote:
>What prompts the computer to
>switch from open loop to closed loop? Does it stay in open loop
>until it receives signals from the O2 sensor or is it prompted by
>some other input that the engine is warm enough to run in closed
>loop operation?
My be I should let DB answer that, but I think that the output of the O2
sensor will
"tell" the computer if its ready to function or not. But even if the car
cannot run on closed loop, there usually are some "limp home" modes that
allow the engine to run reasonably well, even though emissions
suffer. Remember, the main reason for the engine to run in closed loop is
to keep the catalyst happy (which requires a very accurate control of AF
ratio)... D^2
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