Engine Performance problem
1997 Toyota Camry 4 cyl Front Wheel Drive Automatic 170591 miles
My check engine lit up. I used to average over 28 mpg. Now, it's 20 mpg. I went to AutoZone, used their OBD scanner and got these codes. (P0171 Bank 1 system too lean), P0125 (Closed loop fuel sontrol insufficient coolant temperature, P1130 and P1135 ( Manufacturer control fuel air metering).
What can I do to fix this.
Thank you very much,
* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)
* Dirty fuel injectors. (Try cleaning the injectors)
* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)
* Leaky EGR valve. (Check operation of EGR valve)
* Leaky PCV Valve or hose. (Check valve and hose connections)
* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires