If you are looking for accurate AFR readings Pre-turbo or just want to know what your back pressure is then the 7767 is for you. When combined with the 7766 NTK wideband module you can read AFR accurately with up to 75psi of back pressure. With other widebands this is not possible due to their lack of back pressure compensation. You can use a single 7766 and 7767 module to get per bank information on your engine, or use 4 7766 modules with a single 7767 to get per cylinder AFR readings on your 8 cylinder turbo charged engine. You can easily pair the 7766 and 7767 with a Power Grid for plug and play operation or use the supplied analog outputs on each module to read AFR and back pressure data on your data logger or EFI system of choice.