How to Fix Upstream Oxygen Sensors?

Answer Your vehicle's computer uses oxygen sensors to monitor and adjust the ratio of fuel and air being pumped into your engine's combustion chambers. Newer vehicles--post 1990, typically--have at least ... Read More »

Top Q&A For: How to Fix Upstream Oxygen Sensors

Difference Between Upstream & Downstream Oxygen Sensors?

All post-1996 vehicles have a lot of emissions equipment, including oxygen sensors. Most emission-controlled cars have two to four oxygen sensors, depending on the amount of cylinders and exhaust p... Read More »

How to Fix the Upstream Oxygen Sensor on a VW?

The oxygen sensors on your VW are used by your vehicle's computer to monitor and adjust the fuel-to-air ratio in your engine's combustion chambers. The upstream sensor measures the emissions flowin... Read More »

What Is an Upstream Oxygen Sensor?

Oxygen sensors, like anti-lock brakes and radial tires, are one of those little automotive inventions that went from nonexistent to ubiquitous practically overnight. The O2 sensor is your engine ma... Read More »

Is the bank 1 oxygen sensor the upstream?

It depends on whether it is located in the exhaust stream before the catalytic converter. In single-exhaust systems, Sensor 1 is upstream and Sensor 2 is downstream. In dual-exhaust systems, Bank 1... Read More »