EML light on-code P0171

1. carl64 L-plater Joined: Dec 2012 Ilkeston Posts: 80 Saxo 1.1 2001

   #1 11th January 2013, 14:32

   Hi guys, as the title suggests really,used a Snap-On Code Reader, it told me, P0171-Adaptation Mixture Control, I was like "What the hell?". I also looked through the Data.........O2 sensor after Cat Inactive at Idle but Active when revved........Cat Inactive at all times, anyway I cleared the fault code and didnt start the engine again until this morning. The EML light stayed OFF only until the engine coolant Temperature Gauge was reading just over half its normal running temperature. Can anybody point me in the right direction? Or had this or a similar problem to this?
2. smiith Saxperience Hardcore! Joined: Sep 2007 Jail - Whitby Posts: 15034 520bhp Honda Jazz

   #2 11th January 2013, 14:38

   You need a new lambda sensor, the one after the cat..
   
   It will be saying the cat is infective because its taking wrong reading from that lambda, and thinking the cats fucked.
   Temp gauge might be the car thinking its running lean or something, so adding more fuel, and running a bit warmer

   1 user thanked this post: carl64
3. carl64 L-plater Joined: Dec 2012 Ilkeston Posts: 80 Saxo 1.1 2001

   #3 11th January 2013, 16:35

   Oh right, so its not the idle control valve? as the OBD2 reader was suggesting?
4. smiith Saxperience Hardcore! Joined: Sep 2007 Jail - Whitby Posts: 15034 520bhp Honda Jazz

   #4 11th January 2013, 17:14

   P0171-Adaptation Mixture Control
   
   That is what the reader was saying?
   
   Mixture control is done by lambda's, not by the idle control valve
5. carl64 L-plater Joined: Dec 2012 Ilkeston Posts: 80 Saxo 1.1 2001

   #5 11th January 2013, 17:17

   yh, thats what the reader was telling me mate, so I need a Lambda sensor? Post cat?
6. smiith Saxperience Hardcore! Joined: Sep 2007 Jail - Whitby Posts: 15034 520bhp Honda Jazz

   #6 11th January 2013, 17:20

   I'd say it looks that way, if its saying the cat is inactive, its because the lambda after the cat is picking up the wrong readings, so feeding the ECU bullshit.. So it will be saying the cat's not working, but it will be, the lambda will just be picking up wrong readings

   1 user thanked this post: carl64
7. carl64 L-plater Joined: Dec 2012 Ilkeston Posts: 80 Saxo 1.1 2001

   #7 11th January 2013, 17:22

   Thanks mate, I will try and source a good second hand one from somewhere, I hear they are quite expensive new?
8. Bedford126 Saxperience Post Whore Joined: Jul 2010 Morley, Leeds Posts: 8469 Civic ep3 type r powered by TDI NORTH

   #8 11th January 2013, 17:22

   OBD Code P0171refers to running lean error code.
   
   Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.
   
   That's what my Citroen software gives for the code mate.
   
   swap the lambda out for a genuine citreon one or a bosch or delphi Stay away from ebay/euro car parts shite they are around £50-60
9. carl64 L-plater Joined: Dec 2012 Ilkeston Posts: 80 Saxo 1.1 2001

   #9 11th January 2013, 17:28

   I wondered why I got nearly 50mpg.........not bad for town driving, haha!
10. carl64 L-plater Joined: Dec 2012 Ilkeston Posts: 80 Saxo 1.1 2001

    #10 11th January 2013, 17:39

    Thanks for your help mate I will remember that!
11. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

    #11 11th January 2013, 18:15

    Quote:

    Originally Posted by carl64 I wondered why I got nearly 50mpg.........not bad for town driving, haha!

    Good in a way but it won`t be doing your engine much good to leave it like that.