Q: Was does system too lean bank 1 and bank 2 mean?

If you have codes stored in the engine computer for lean bank 1 and 2 is caused by the entire engine is running lean. This is caused by not enough fuel getting into the engine or too much unmetered air getting into the engine and the computer cannot compensate anymore to run it normal. Have the engine fuel pressure checked and also check the engine for any vacuum leaks. If further diagnosis is needed then contact a mechanic like one from YourMechanic to do more diagnostics if problem is not found.