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Old 06-28-2018, 12:43 PM   #7
Clipdat
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Isn't this counter intuitive though? Have you ever stood behind the car when it's doing it's high rev cold start routine? It smells absolutely disgusting and stinks up the entire area around the car within a 20+ foot radius.

Seems like it's belting out exhaust emissions at a higher than normal volume & velocity during this time, thus polluting more.

Quote:
Originally Posted by Ultramaroon View Post
The cold start behavior has a purpose. It is to further reduce emissions by immediately preheating the primary catalytic converter. It does this by setting the spark timing much later than normal so that the fuel is still burning as it hits the cat.
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