1997 Volvo 850 fuel too rich

1997 VOLVO 850
14,500 MILES • 6 CYL • 2WD • AUTOMATIC
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YUSSEL
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The engine light keeps going on and the diagnosis by our mechanic is "fuel too rich". We have already replaced 2 oxygen sensors and a part of the fuel injection systyem
but the light keeps going on and the diagnosis remains the same (fuel too rich). We tried changing fueling stations but that didn't work.
What do we do?
Jun 8, 2009 at 6:28 PM
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RASMATAZ
  • ASE Certified Mechanic
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  • ASE Certified Mechanic
1997 Volvo 850 fuel too rich

Typical symptoms of an engine that is running rich (too much fuel, not enough air) are poor fuel economy, elevated emissions (Carbon monoxide or CO), and engine may have rough idle or surge condition.

Possible causes include a bad O2 sensor, excessive fuel pressure (bad fuel pressure regulator or plugged return line), leaky fuel injectors, dirty air filter or restricted air inlet, or a defective coolant sensor that prevents the engine management system from going into closed loop mode
Jun 8, 2009 at 6:47 PM
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