HOW DO U KNOW IF U NEED UPSTREAM OR DOWNSTREAM.

Question

I GOT CODE P1155 HEATER MALFUNCTION ON MY 01 SOLARA 3.0 TRYING TO FIGURE OUT WHAT SESOR TO CHANGE AND WHAT THE PART # IS

Answer 1

You need Bank 2 Sensor 1 it is also called an air to fuel ratio sensor.

it will be the radiator on the exhaust manifold.