Z3 1997 M44 ODB code P1423 Secondary Air System

The air pump was replaced by the previous owner. Now, about 6 months later, I am getting these codes again. Are there any common problems associated with this system? I am suspecting a sticky vacuum vent valve. Any ideas?

Reply to
Leonard Caillouet
Loading thread data ...

P1423's are a classic Z3 problem.

The key is to replace both the check valve *and* the air pump, not just the air pump. The check valve is root of the problem: it's letting water vapor from the exhaust manifold flow into the pump, which is corroding the pump.

I _was_ going to replace just the air pump, but my BMW technician buddy strongly suggested I replace the check valve as well, otherwise the pump would fail again quite soon. 30,000 miles later, and the air pump is still doing fine.

[ BTW, the part numbers/prices are: [ o check valve, $94, BMW p/n: 11 72 1 744 255 [ o air pump, $268, BMW p/n: 11 72 1 432 907 [ [ Reference:
formatting link
Reply to
Ted Johnson

Good info. Thanks.

Leonard

Reply to
Leonard Caillouet

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.