Citroen Xantia (1993 - 2000) - 1996 1.8 16v - error code number 31

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Tue 3 Jun 2008 17:35
1996 1.8 16v - error code number 31 - rip
My xantia is using to much fuel, i had it on a cit diagnostic tool and came up with code no 31- this has about ten items which could be the fault- from ignition system to wiring to air filter and spark plugs (which I have changed recently- so these are ok). one of the other options was lambda sensor.

The car drives absolutely fine, the last mot shows emissions fine- however the garage think based on the list of potential items on code 31 and the fact the car drives perfect the most likely fault item is the lambda sensor, does anyone have any experience or ideas regarding this code or lambda sensor theory?


Btw the engine management light use to take four seconds to go off when the engine was started and use to remain off. Now the error code has been removed the light goes off immediately- this may or may not be relevant.

All help appreciated

Edited by Webmaster on 03/06/2008 at 17:49

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Tue 3 Jun 2008 17:47
1996 1.8 16v xantia- error code number 31 - rip
i should also add due to the age of the car it would not give more specific results
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Tue 3 Jun 2008 18:03
1996 1.8 16v - error code number 31 - Screwloose
rip

"Mixture control" as a code definition is a lot of help - not!

For a fairly crude self-diagnostic system to pick that up it must be over-fuelling quite a bit. Why didn't they go through all the mixture-relevant sensors in live-data while it was plugged-in? Codes are rarely much use to pin things down.

I'd think check/clean MAP sensor first; then check coolant sensor; TPS and only replace the oxy sensor if it won't respond to provocation. A good man with a 4-gas analyser could tell a lot.
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Tue 3 Jun 2008 18:58
1996 1.8 16v - error code number 31 - rip
they said due to the age of car its not possible to do live data- only from 98 onwards is this possible- apparently
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Tue 3 Jun 2008 18:59
1996 1.8 16v - error code number 31 - rip
forget to add according to the reader there is a slight misfire over 2000 revs too.
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Tue 3 Jun 2008 19:03
1996 1.8 16v - error code number 31 - Screwloose
It's a Sagem SL96 - of course it supports live-data. [Whether their tool can read it....?]

So; if it was codes-only; where did the misfire show-up? That could well be the cause of the code - unburned oxygen.

Edited by Screwloose on 03/06/2008 at 19:05

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Wed 4 Jun 2008 01:59
1996 1.8 16v - error code number 31 - rip
screwloose thanks for the replys

i think the injection is bosch mp5.1.1, whereas the sagem is for 98 on models, would this make a difference?
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Wed 4 Jun 2008 14:29
1996 1.8 16v - error code number 31 - Screwloose
rip

My continental reference data says the SL96 came out in '96; [the Sagem S2000 came out in.... You've guessed it.]

There certainly were Xantias with MP5.1.1 systems prior to that [and MP5.2 as well] but it was the Motronic MP7.3 that came out in '98.

However being both French and a Citroen; what should be on it, rarely seems to be what is actually fitted, so Bosch it is - still should have basic live-data.
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Mon 21 Jul 2008 17:22
1996 1.8 16v - error code number 31 - gochoo
Hi all, I have Citroen Xantia 2000 and I need to read fault codes, clear check engine light etc. What tool and software should I use? It has Bosch Mp5.2.
Thanks in advance.
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