These are replacement oxygen sensors for the B9/B9.5 Audi S4, S5, or SQ5. It is critical to replace these sensors if you have any trouble codes linked to the bank 1, sensor 1 or sensor 2 oxygen sensors to ensure your car is running properly.
034Motorsport commonly sees these sensors fail after reinstallation from over-torquing, causing internal code errors in the oxygen sensor and recommends replacing if your vehicle displays any abnormal oxygen sensor faults.
Examples of codes where 034Motorsport recommends replacing the Front/Rear oxygen sensor: P0031, P0130, P0131, P0134, P0036, P0140, P0141, P0144. Sensor 1 refers to the oxygen sensor located in the turbocharger and is the Front oxygen sensor. Sensor 2 refers to the oxygen sensor located after the factory catalyst and is the Rear oxygen sensor.