HiSport Wideband Oxygen Sensor 234-5107 - Heated O2 Sensor Replacement for 250-25035, 5-Wire Air Fuel Ratio Sensor,1 Upstream, Compatible with Audi A3/A3 Quattro/TT/TT Quattro, VW Passat and more

Where are Oxygen Sensors Located?

• All vehicles built after 1996 normally have at least 2pcs oxygen sensors
• V-6 and V-8 engines will usually have 3 or 4 pieces of oxygen sensors, 4 cylinder engines will have 2pcs oxygen sensors
• The O2 sensors will have 1-4 wires on them
• The front oxygen sensor(s) will be located under the hood, on the exhaust side, near the engine
• The rear oxygen sensor(s) will be located under the vehicle, directly after the catalytic convertor.

How Does the Oxygen Sensor Work?

This upstream oxygen sensor is related to the catalytic converter. It measures the air-fuel ratio of the exhaust coming out of the exhaust manifold and sends the high and low voltage signals to the powertrain control module in order to regulate the air-fuel mixture.

When the powertrain control module receives a low voltage (lean) signal, the oxygen sensor will increase the amount of fuel in the mixture to compensates. When the powertrain control module receives a high voltage (rich) signal, it leans the mixture by reducing the amount of fuel it adds to the mixture.

Is it Hard to Install?

yes.

Normally replacing an oxygen sensor is a quite straightforward procedure that usually only requires a few tools.

One thing you must ensure that the oxygen sensor must be completely the same as the Original.