View Single Post
      05-19-2011, 01:55 PM   #12
Zba
Lieutenant
 
Zba's Avatar
 
Drives: 2011.685 E92 M3
Join Date: Feb 2011
Location: Denver, CO

Posts: 557
iTrader: (0)

Garage List
2011.5 M3  [4.87]
Quote:
Originally Posted by Jaypod View Post
I *think* the secondary air pump is only used for cold starts to provide fresh air to the cats. Not sure what would cause it to fail other than it being an electric part which would no doubt fail eventually.
Correct, sends O2 into the exhaust stream on a cold start (rich condition) to help burn off excess hydrocarbons (unburned fuel). In it's location above the engine it is exposed to some pretty high temps, so yeah...
Back on topic!

Crazy rotor!
Zba is offline  
0
Reply With Quote