AEM Wideband UEGO Controller allows easy monitoring of air-fuel ratios from the standalone EMS at highly affordable price. Monitoring your wideband air-fuel mixture allows you to accurately gauge the engine's fuel condition, which aids in engine tuning and also prevents engine failure. The best part of AEM Wideband UEGO Controller is its ability to work on all engines - from 4-cylinder to V10 applications. It's no surprise that it is getting all the rave reviews from the market.