Secondary Air Pump

Service Engine Soon Light has tripped and scanning for codes comes up with the Secondary Air Flow low to cylinders 1-3 and Secondary Air Flow low to cylinders 4-6. Electrical connections to air pump and the hoses are ok. My question is: is there any serviceable parts to the Secondary Air Pump or is it time to replace?

Oh, forgot to add that it is a 2003 330xi Sport with slightly over 121,000 miles.

Are you sure it's the SAP itself or a leak in the vacuum lines?

To answer your questions, you should be able to replace the valve that diverts air flow to the cats. If you determine the air pump itself is defective, it's time to replace the system (pump and valve) or install an SAP sim to the system.

If the small vacuum hoses are broken the car will throw a p0491 and p0492 like mine did.
This could be a cloggeg EGR valve or the air pump isn't pushing enough air. Get a mityvac from autozone and test the system.

Tom...hey, what's up?

First, feel the hose from sap to valve...if it's squishy, remove it from valve and look inside the inlet...mine got clogged from decayed hose material getting blown into that port. Replace hose if you find that.

Also, particularly if you've done anything recently around there, like vcg, the vac hose leaving the valve connects to a hard plastic hose that's very brittle...wraps around behind the manifold. Remove cabin air filter housing and you'll see where it's supposed to connect to.

If you search for me in my thread with 'intake manifold' in it, flashmeow posted some pics of the manifold out of the car...very helpful if you need to get back there. Anyway, that vac line is brittle.

Final thing might be to pop the cover off sap and see if maybe that filter is in dire straights. If so, I 'made' a replacement from a Briggs and Stratton lawnmower filter Better than a $300 pump, huh?

GL...hth

Ill sell you my SAP for $100 shipped!

Here is a great resource for troubleshooting the secondary air system:

http://www.bavauto.com/newsletter/20...newsletter.pdf

Probably a clogged secondary valve right there at the exhaust. I would take it off to see if it is clogged and clean it if it is.

Just did mine 2 weekends ago and get this fixed before the pump croaks or it'll get quite a bit more costly than if the pump is still working. I think someone linked the Baverian Autoworks tech article but if not find it and use it.

On my 02 330xi it ended up being a cracked vacuum hose wich caused the valve to stay shut and burn out the air pump and seize the valve. Got all my replacement parts from BMA, by far the cheapest but it was still about $350 for everything including new hoses, valve, pump and rubber pump mounts. The valve comes with a gasket already so no need to order that additionally.

Not a hugely hard DIY, so save the $$$$