2003 Toyota Solara Q&A
2003 Toyota Solara Question: Which O2 Sensor is the B2, S1. And is it upstream or downstream?
that would be an upstream, sensor is located in or near the exhaust manifold, would be a better option to replace both bank 1 and bank 2 sensors at same time.. - Tbone1980
bank 2 is the side closest to the front of the car.sensor 1 is the upstream or pre-cat. - joelburke26