Has anyone attempted a deletion of secondary air pump. Some people say its not needed. Some people say it (deletion) will foul up the CAT and O2 sensors. This is a fairly expensive singular part. Anyone have suggestions? I most likely will replace the valve controlling it first to see if that clears up the check light.
I don't know about the delete, but I have heard that if you replace only the valve, you will end up with the same problem again unless you take care of the problems cause. This is one of the issues that a dealer was needed for, but that may be due to it occuring on the E39. It's better to pay long dollar to get it diagnosed and corrected than to have it fail over and over again, IMHO.
My car hasn't had a SAP since 1997. Cat is fine. 02 sensors go from time to time like any other BMW. I had my software rewritten so it wouldn't look at the SAP.
Be good to your car and the air. The secondary air pump only runs the first few minutes after start up, true, but it's to help heat up the oxygen sensors and cat to keep the air clean. Not sure if it will appreciably shorten the life of those parts. And as another writer suggested, if you replace the pump, might as well replace the valve, too. But just because you're getting faults saying secondary air system does not necessarily mean it's the pump. When you first start the car, can you hear, feel the pump running? If not, it's quite possibly the pump.
I've found it's usually the valve that goes bad and allows condensation to form in the pump, trashing it in short order. I replaced the valve and the un-repairable pump on my kids' 1998 318ti but I got it aftermarket (Pierburg brand just like OE) for about half of what the BMW dealer wanted for it. Still not cheap, but at least it's done right. It really is a stupid, Rube-Goldberg solution to a problem that only exists in the OBD-II mind of EPA. Actually, I didn't know a '96 ti had an SAP since I just looked at a '97 the other day and it had something else in that spot other than a pump. Some kind of canister?