Which Oxygen Sensor should i buy ??

Question

Hi, i ran a diagnostic and have a engine code (p0135) for oxygen sensor1, bank1. My issue is, which one should I buy... upstream (left or right) or downstream? ..

Answer 1

Hi there,

Sensor 1 is the upstream sensor, bank one on this is the one closest to the firewall. This would be the left bank in most cases. Also, left and right upstream are likely the same part #