Just wanted to say that I'm glad you solved your PITA SAS/SAP problem, Alex.
Just for clarification the SAS system pumps air and hence oxygen directly into the exhaust manifold and exhaust system to help the CATs light off quicker thereby reducing cold start emissions sooner. Since the upstream O2's are in open loop during cold start and warmup, they are used by the ECU to detect a lean mixture which means that the SAS system is working. If the O2's detect a richer mixture, they indicate low or no flow from the SAS and set fault codes accordingly. Once the O2's go into closed loop, the SAP has shut off as has the vacuum to the check valve and the SAS job is done and the upstream O2's go back to their normal job of feeding the ECU info for mixture control.
johnstern;7122440]Yeah! I thought you had solved your SAS chu, chu problem when you replaced the IM gasket, but I guess it was not to be.
Nah! Not now, maybe someday. The old one has only been in there a year and died prematurely!Are you going to repair your old pump using CNN's DIY on Bimmerforum? It would be nice to have a spare pump around. Of course that's assuming that a ruined bearing is what's wrong with the pump.
As I mentioned in other threads, the Volvo people have bypassed the SAS system using a diode.
If some geniuses from this forum can figure out how to do this on the E39, it'd be golden!
Here is the Volvo trick: