'98 E320 check engine light --codes P0161,P0170,P0460
 

Help--Got this car back from Mercedes dealer to have 4 tires installed and after 10 miles set check engine light. Pulled following codes:
P0161--Bank 2 02 heater circuit
P0170--Fuel trim Bank 1
P0460--Fuel Level sensor A circuit malfunction.

History: Car had P0170 and P0173 codes about 500 miles ago--replaced Maf with known "good" used maf--reset check engine light and now the above has occured.Can someone tell me which sensor is "sensor 2" is it before or after the cat? Which side of the motor are they refering to when they say "bank 2"?
What is a "fuel level sensor? What is the Fuel level circuit A?


Any help and suggestions will be greatly appreciated.