View Single Post
Old 11-08-2017, 06:49 AM   #9
Lapister
Registered User
 
Join Date: Dec 2014
Location: Pasadena
Posts: 261
Cat converters can't do their job to burn off emissions till they heat up on cold starts. Hence air is injected by the pump to dilute the mixture during cold starts. The pump runs for 90 sec whereby after the converter is hot enough to continue its job. Most euro cars including VW, Audi, utilize this system. What a pain for those who have to work on these!
Lapister is offline   Reply With Quote