Mazda 6 Possible 02 Sensors or Vac Leak?
 

Hi, i felt that I needed to post this because it felt like a unique problem, but IDK. My 2004 3L V6 Mazda 6 it throwing a lean bank 2 (p0174), which I know is no special thing, but it had previously been pending a lean bank 1 and a Warmup catalytic converter problem (P0171 and P0421). It had been showing the lean bank 1 and lean bank 2 problem for a while, and I did just replace a vacuum line, so I am not sure what to do at this point. Any help?