545i increased emissions (SES)
 

The car is a 2004 545i v8 6speed man trans. 145,000 miles

Ok so the last month I have gotten the SES and increased emissions.

The code that is coming up is for cylinder bank 2 secondary air.

It's only popping up when I get to just above 1/4 tank of fuel. I top off the fuel, give it a few 5k shifts and within a day or two the code goes away. Maybe my secondary air ports are becoming carbon clogged or the solenoid is failing? Any advice before I take it in to have it looked at would be appreciated.

Thanks
Garrett