Mechanics

KEEP GETTING ERROR CODE PO171

1996 Ford Contour • 160,000 miles

I have replaced Fuel Filter, Air Filter, MAF Sensor, New PLUGS, THERMOSTAT, WITH OLD MAF SENSOR HESITATES ON ACCLERATION, POOR GAS MILEAGE MAYBE 250 MILE PPER TANK, WITH NEW MAF SENSOR MISSES AT IDLE GETS A LITTLE BETTER HAS IT WARMS UP, HAD INJECTORS CLEANED, I USE TO GET 400 MILES PER TANK, DON, T KNOW WHAT ELSE TO TRY? MAYBE FUEL PUMP, EGR VALVE, PVC NO LEAKS, INTAKE MANIFOLD NO VACCUUM LEAKS, HELP PLEASE
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Wayneweatherman
September 22, 2012.



Which engine do you have?

KHLow2008
Sep 22, 2012.
Also has new o2 sensors, It has a 2.0 16 valve Ztech motor

Tiny
Wayneweatherman
Sep 22, 2012.
These are what can cause a P0171

HO2S and sensor connection.
Vacuum systems.
Fuel injector and/or fuel injector circuitry.
Powertrain Control Module (PCM).
Electrical circuits (HO2S, HO2S GND, INJ 1-8, VPWR and SIG RTN).

To prevent replacement of good components, be aware the following non-EEC areas may be cause of driveability concerns: Ignition system.
Faulty evaporative emission system.
EGR and/or PCV system.
Air intake system.
Engine oil contamination.
Fuel system.
Exhaust system leaks or restriction.
Engine cooling system.

A scan tool would help for diagnostics.

KHLow2008
Sep 22, 2012.