Pressure Sensor 0-75 Psi With Harness Optional, Second Pressure Sensor And Wiring Harness For The 7767 Exhaust Pressure Module MSD IgnitionIf 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