1996 Honda Civic Code PO171

1996 HONDA CIVIC
150,000 MILES • 4 CYL • FWD • MANUAL
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MIEKODAMONKEY
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I recently got the engine code po171 (bank 1 too lean). So as suggested by a mechanic, I replaced the map sensor, fuel filter, pcv valve, and sprayed down the O2 sensor with electric compononent cleaner. But the code is still comes up and im getting about 22mpg compare to my 30-31mpg before this code came up. Any other suggestions that you might think what the problem is? thank you in advance.
Sep 5, 2008 at 10:50 AM
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KHLOW2008
  • ASE Certified Mechanic
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Hi miekodamonkey,

I would test the primary HO2S sensor and replace it if out of range.
Sep 7, 2008 at 10:11 AM
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MIEKODAMONKEY
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Should I vacuum leak check it first before I buy a new O2 sensor to make sure there are no leaks?
Thank you for your response.
Sep 7, 2008 at 10:44 AM
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KHLOW2008
  • ASE Certified Mechanic
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If the idling speed is below 800 rpm, then it should not be a vacumn leakage problem. Anyway you need to test the HO2S resistance and voltage first.
Sep 8, 2008 at 8:05 AM
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MIEKODAMONKEY
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I have changed the primary O2 sensor, and the engine light is still on and my mpg is still about 22-24 compare from 30-31 from the past. Do you have any ideas of what I have to fix?
Sep 13, 2008 at 3:25 PM
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KHLOW2008
  • ASE Certified Mechanic
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Hi miekodamonkey,

Is the code still same?
Lean mixture can be due to
1. vacumn leakages.
2. low fuel pressure or clogged fuel filter
3. faulty injectors.
Sep 14, 2008 at 1:59 AM
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