Getting bad gas mileage? Please Read.

I was getting pretty bad gas mileage so I did a KOER test with a code tool. I found out my ECT was out of range. It also wasnt creating a check engine light. So I replaced the sensor and my gas mileage seems to have gone up. Ive put about 50 miles on it and the gas guage still reads full. Also the temp guage wasnt working and always read around 130. I replaced the sending unit for it and now it works. I know this topic has come up before and thought maybe I could help out some people out with this info. Both parts cost about $30.

mustangrfast88: I had already done a tune up. New cap and rotor, plugs, plug wires O2 sensor, fuel filter, pcv valve, changed tranny filter etc, etc. When I ran the KOER it told me the ECT was out of range. If the ECM never thought the car was warm it would always run in open loop (or is it closed loop?) which would hurt fuel economy.
realtripp: The ECT is the Engine Coolant Temp. sensor. It tells the ECM what the engines coolant temperature is.