OBD II code help

[BimmerRacer007]

ok guys, so i received the error code P0170 which is fuel trim bank 1 fault. is this for pre-cat O2 sensors? MAF sensor? anyone know?

oh yeah, it's for an s52 in my z3 as well. (i know it's not an e36 in the traditional sense, but it's the same powertrain. im trying to get this fixed to pass emissions. lol)

thanks!

Dan

[palmspringstigr]

Hi. I don't have any experience with your type of engine. Yet, I have found this site useful on the service codes for some of my M52 engine problems.

http://www.bba-reman.com/

Good Luck.

[BimmerRacer007]

thanks, yeah i found out that the code means fuel trim management bank 1, but i just don't know what part that means... from what i can tell, bank 1 means it's affecting cylinders 1-3 only, which leads me to believe that it's an o2 sensor (most likely pre-cat) for the rear 3 cyls and not a complete MAF sensor failure or vacuum leak. i just don't wanna drop hundreds in parts that aren't the problem.