2001 GMC Sonoma Emissions Test Failure

(I have made a donation via Pay Pal receipt 9L945448EB8267410. There were 3 error codes on my emissions test result. The Oxygen sensor was bad and has been replaced. Two errors remain. P0178 "Fuel Composition Sensor Circuit Low and P0179 Fuel Composition Sensor Circuit High". The repair station told me they don't know what they mean. I called the State authorized repair station and they told me that the sensor would be $1000 to replace and may not solve the error codes. They are not sure if it is due to my engine being an E-85 engine and the sensor is expecting ethynol mixture of 30% or higher but Texas uses a 10% ethynol mix. Any info will be good. Should I bet the $1000 and change the sensor? One shop told me that if the sensor failed it would throw an Fuel Comp. Sensor Failure code. I don't know. I just don't have the cash to just gamble on it working.