Quote:
Originally Posted by thom4782
Thanks for the info. -10C to 42C is roughly 14F to 105F. I guess this means that the secondary air pump will operate if the engine is cool or cold for the most part. For lots of the US, the outside air temperature is between the range limits on most days.
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I don't know if Porsche is doing this for the newer cars but I've seen cases (U.S. cars) where SAI kicks in when the engine is idling for a long time because the "pup" cat and upstream O2 (actually, A/F ratio sensor among other names) have cooled down enough to cause the feedback function to go open-loop (also turns on the O2 sensor heater when this happens). With emission requirements getting more strict, I'm also seeing (from many OEMs) the downstream O2 sensor being part of that feedback loop which it wasn't when it was implemented for OBDII (1996) to check on the oxygen storage in the cat.
Times are changing and things are getting more complicated...............
Regards,
paul...