A few weeks ago my SES light came on. I checked the gas cap and filled up a few times and this did not correct the problem so I took it to the shop (NOT a BMW dealer) and he said it was coding for an emissions pump. He said the pump sends air into the engine to clean it to reduce emissions and it is no big deal unless I need to go thru inspection or the car starts running badly. He re-set the computer and off I went. The light came back on and I read a few posts on this site and took it to Auto Zone to have the codes read. They said it is a PO491 & P0492, Secondary Air System, banks 1 & 2. I called the dealer to see if this is covered under emissions warranty and they said they use a different code reader and it will be $124 for diagnosis w/their computer...total BS. Does anyone know what this means??