I am getting the code for lean in bank 1 and 2
 

I hav a 2008 endeavor and I am getting the code for lean in bank 1 and 2, I have replaced mass air flow sensor. Could I be the fuel filter or o2 sensor? Any one have any suggestions, and if it is the fuel filter where is it located? I cannot find it anywhere?

Hi, Fuel filter will not cause those codes. I highly doubt that 'both' Ox sensors went bad at same time.
> Why did you replace MAF? Running poorly?
> Are you sure there are NO leaks when you installed MAF sensor ?
Since 'both' banks are showing lean, there must be a common fault that would apply to both.
Leak 'after' MAF, leak in intake manifold, vacuum hoses...
Check all those before throwing parts at it.
Also, Google " lean- both banks", and fault codes for potential faults/remedies.
HTH.