Bank 1 and Bank 2
What is Bank 1 and Bank 2?
Bank 1 and Bank 2 simply refer to either side of the engine. Check your owner’s manual for definite clarification of upstream (Bank 1) and downstream (Bank 2) banks. Bank 1 is most commonly found by the front most cylinder on the engine (Cylinder 1), and Bank 2 is the opposite side of the engine. In each of these banks you can usually find respective O2 sensors