In the world of modified cars, a Wideband O2 sensor is a very useful diagnostic tool. In this article we explain the purpose of Wideband O2 sensors, and give some reasons as to why every modified car should have a one.
What is an Air Fuel Ratio (AFR)?
Internal combustion engines require tightly measured quantities of air and fuel to be present in the chamber for ideal performance. Modifications to your engine, such as air intake changes, fuel system changes, different fuels, or power adders such as camshaft swaps, Nitrous, turbos or superchargers all have an impact on the amount of air or fuel required by the engine during each combustion cycle. It is the ratio of Air to Fuel (AFR) that is critical to achieving the best from your engine.
Wideband O2 sensors monitor the amount of oxygen in the exhaust to measure the Air Fuel Ratio, or AFR. The AFR tells your tuner whether the car requires more or less fuel to achieve the best power or economy, and allows your tuner to keep the engine safe.
Monitoring your AFR
To view your AFR we recommend our TechEdge 2J Wideband O2 Controller kit. These kits come with everything required to allow you to log your AFR along with 5 other sensors inputs (ie. tacho, road speed, throttle position, intake temperature), and allow you to view this on your laptop.
To monitor in car, we recommend one of the TechEdge gauges, which use a digital connection to the controller for the best possible accuracy.
T.I. Performance sell a full range of Wideband Controllers, Displays and Sensors for all your AFR monitoring needs. Check them out below!
Modifications such as those listed above, along with age, wear and tear on components can cause the AFR to drift either too lean, or too rich. Lean conditions can cause detonation, or pinging, which will severely damage an engine if left unfixed. Rich conditions lead to excessive heat, misfires, damaged/blocked catalytic converters, fouled plugs and poor fuel economy. Neither a rich or lean tune is safe; this is why it is important to monitor the AFRs to ensure the engine is receiving the right amount of fuel.
What is the right AFR?
Different engine types and setups or different fuels require different AFRs. For absolute maximum power you will need to measure the affect of changes on a dyno or at the drag strip.
Stay tuned for the next article in this series for more information about targeting the right AFRs in the right conditions.