2004 Nissan sentra is wasting gas, I get 350 miles per full tank of gas. Not sure what is wrong took it to machanic he cleaned out fuel injectors, car worked find for a little bit then started wasting gas again.
1. Excessive fuel pressure can be cause by restricted fuel return line
2. Defective Oxygen Sensors.
3. Leaking injectors and fuel pressure regulator.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.