Quote:
Originally Posted by jfitzpat
The ECU won't even start heating the sensor until it is reasonably certain that moisture is cleared from the exhaust, because a droplet of water will shock cool the ceramic and dramatically shorten sensor life.
The same is true with unburnt fuel. When the engine is cold and intake air is cold, the points are generally out of temp range, which is surprisingly narrow, so there tend to be misfires. Also, when the intake air is very cold, you tend to get partial condensation from the charge. So the ECU waits until all indications are for flame front temps within range and normal valve action - ie, an engine top end that has achieved a suitable operating temp.
Something we are working on is a much more durable O2 sensor. The idea is that you don't have to wait to heat it up, but could start it heating when the door opens or the key goes in the ignition. This doesn't solve the air charge issue, but it helps solve the pig-rich-zero-cat-efficiency intervals.
-jjf
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I won't begin to debate this with you because you obviously know far more about it than I do and I've been wrong before. But, for the sake of curiosity, I will check how long it takes my car to get to CL from cold and see what the temp reads when it does. I was under the impression that the O2 sensor in my car did start to heat as soon as the key was turned on or at least as soon as the engine started. Maybe I'm wrong. Now you've got me curious.