PLEASE HELP,

I have a 98 m3, shortly after i put a dinan throttle body on, my CEL came on Code p1188. I checked and there did not seem to be any leaks. I replaced the fuel filter, still on. Today i changed the O2 sensor. I was a little confused on which sensor belonged to bank 1. I followed the exhaust manifold to the the cat on the driver side WHICH I ASSUME WAS BANK 1 SENSOR 1 AND CEL is still on. Can anyone help?