Secondary air for smog?

2005 BMW 545I
144,000 MILES • 4.4L • V8 • 2WD • AUTOMATIC
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JUSTPYTHON
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  • 4 POSTS
I keep getting the same codes telling me that the car isn't getting enough air on cold start-up on both banks. I replaced the air pump, and I can hear it come on every time I start the car. I've replaced the check valves to both sides, and I still get the same thing after I clear the codes and drive it. Both banks are not getting enough secondary air. I even ran an endoscope camera into the air pipe and into the head. There is carbon but not much at all. The camera can go all the way to the other side of the head with no problem. The car runs great, but I can't get it to pass OBD2 standards. Any help would be great.
Jul 11, 2022 at 3:51 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

The secondary air injection serves as an exhaust gas treatment during the engine warm-up phase. For this purpose, fresh air is injected directly into the exhaust manifold to ensure the catalytic converters heat up at a faster rate. After the engine starts, the secondary air pump is activated by the SLP relay.

Have you checked the relay and fuse related to the pump motor? is everything properly sealed?

Take a look at the schematic below and let me know if both highlighted items have been checked and confirmed as working.

Take care,

Joe

See pic below.
Image (Click to enlarge)
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Jul 11, 2022 at 9:30 PM
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JUSTPYTHON
  • MEMBER
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I'm still trying to get my car to pass smog. I get the same codes 'not enough air on banks 1 and 2. I replaced the air pump, and I can hear it come on for about a minute. If my pump is working that means that my relay must be good, correct?
Aug 3, 2022 at 10:06 AM (Merged)
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