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Pete, Technician
Category: Car
Satisfied Customers: 28792
Experience:  17 years automotive training and experience.
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Nissan/Datsun almera: hi, on an 05 almera 1.8 auto i have

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 05 almera 1.8 auto, very low mileage, 16,000 in nearly 8 years, drives good, plenty of power, idles smoothly, but waiting at lights idle can go down to 600rpm then engine light comes on when you drive off.

  my scanner says P0171 code on its own - lean mixture, but it has high positive fuel trims and spark plugs were sooty which means rich mixture, so is that a bad o2 sensor not working correctly, and if so which brand should i put in a uk almera. thanks in advance


My name is XXXXX XXXXX I am a professional here at Just Answer. I noticed that your question was not getting a response and thought I would see if you still need help with this.

From what you have described here this sounds like you may have a possible failing oxygen sensor before the catalytic converter.

If this sensor is reading incorrectly/stuck at lean readings it will cause the lean exhaust code to set as well as cause the engine computer to richen up the fuel mixture.

If this is replaced it is best to replace it with the factory OEM brand oxygen sensor as this is usually the most reliable for your vehicle here.

Thanks Pete
Customer: replied 4 years ago.

Thanks Pete

It passed its MOT emissions test 2 weeks ago easily so it seemed a bit odd that the sensor would go bad so quickly after the test.

Anyway, better get myself a slotted socket. Have you changed many of these yourself?




I have replaced several oxygen sensors in the past but not particularly on this model here.I would use whatever wrench or socket fit best to change these out.

It is possible this sensor failed soon after it was inspected as most can fail at any given time.

Let me know if you need anything else and feel free to rate my help here when your ready.

Thanks Pete
Pete and 6 other Car Specialists are ready to help you

I am following up with you to see if you still needed help with your question you had asked.If my help didn't satisfy your question please let me know so we can continue.

Thanks Pete
Customer: replied 4 years ago.

hi pete


am waiting to receive items, socket and sensor, i'll let you know if it's successful or not





Sounds good.Let me know if you need anything else in the future.

Thanks Pete
Customer: replied 4 years ago.

Hi Pete


Just fitted the new sensor, drove it for 20 miles, plugged my scanner in and everything is fine, fuel trims back to zero etc, so it was the sensor after all.





Thats great to hear.Let us know if you need anything else in the future.

Thanks Pete