Top 5 Best Wideband Gauge Reviews 2018 Wideband gauge sensor is also known as the wideband O2 sensor that measures the ratio of oxygen to fuel vapor within the exhaust exiting the engine. The ratio is expressed as parts of oxygen to fuel. You need to know that there are 15 parts of oxygen to every single part of fuel. This is why the ratio is expressed as 15:1. Due to the presence of aem wideband gauge sensor, it becomes easier to measure the air to fuel ratio in an easier way in a broad … [Read more...]