Smog pumps

Sal Lubrano

Active Member
Joined
Apr 26, 2002
Why do some manufacturers install secondary air pumps / smog pumps while other don't? I understand why they are installed. To pump oxygen on cold start helping with hydrocarbons. If some manufacturers can get away without installing them, why waste money? For those cars without them how do the manufacturers keep the emmision levels on cold starts?
 
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