In need of assistance

Okay, my car has had the CEL on for about a month saying it was lean bank 2. I had tried basically everything I could think of to fix it with no luck. Check vac leaks, cleaned Maf, blah blah blah. Then it really started running like crap. Took it to advanced and now its misfiring cylinders 2,4,6, lean bank 2, and an 02 sensor is out.

I took the fuel rail off today and cleaned it out, nothing. Im guessing its injectors, but i just dont see how all three would go out at one time...

Any input would help me tremendously.