Flex Fuel Sensor 12570260 For Chevrolet Silverado Tahoe GMC Yukon 4.8L 00-05{Advantage} The Flex fuel sensor can monitor the ethanol content of the fuel in your flex fuel vehicle. The flexible fuel sensor signal is used by the engine control module to adjust the ignition timing to achieve efficient operation.{Attention} The flex fuel sensor can eliminate P0178 P0179 error codes, no longer check engine lights, and no longer rough start. All components are strictly inspected and verified to meet the most stringent quality