Saxo Mot fail- faulty lambda sensor?

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isisalar
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Saxo Mot fail- faulty lambda sensor?

Post by isisalar »

Hi guys,
Had a new exhaust and post cat lambda sensor fitted to the 1.1i Saxo back in November, shortly after, the EML came on so suspect lambda probe problem, haven't had a chance to get it on a Lexia yet.
Had the car mot'd early, yesterday, failed on bottom ball joint cover, indicator bulb not yellow enough, dipped beam bulb gone(hopefully), all simple enough.
The worrying failure is:- 'Exhaust emissions Lambda reading after 2nd fast idle outside specified limits (7.3.D.4)'
I will be getting it on a Lexia asap but could anyone say if this points toward a failed sensor or could it benefit from a much needed service? Would removing the air filter help with this reading?
Jaystock who supplied the exhaust and sensor will return the item for a warranty claim but won't do an exchange.
Prices of new sensors vary wildly from £30-£130 any recommendations?
Could really do without all this aggravation this time of year, this is the first petrol car I've had for 20 years, and I think it's going to be the last.
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
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Re: Saxo Mot fail- faulty lambda sensor?

Post by RichardW »

Could be the sensor, but you'd need to know what the lambda number was to see if it was rich or lean - changing the air filter is not going to make a difference if it's lean :-D
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isisalar
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Re: Saxo Mot fail- faulty lambda sensor?

Post by isisalar »

Thanks for that Richard, I've checked the result and the first test was 1.044 the second was 1.036, limits being 0.97-1.03, apparently this indicates it's running rich.
I feel a service coming on, let's pray for dry weather.
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
citronut
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Re: Saxo Mot fail- faulty lambda sensor?

Post by citronut »

were did the Lambda sensor that is fitted come from, ( not the E bunch,
as i have had a Bosch boxed one from them that didnt even kick in at all on the re/test,

and my MOT guy will/does spend a lot of time trying to get the thing hot enough to switch in
Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years
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Re: Saxo Mot fail- faulty lambda sensor?

Post by wheeler »

Theres no point in guessing at this, its the easiest way to waste money, first things first with the engine warm & idling get it on lexia & see what voltage readings you are getting from both oxygen sensors, the upstream one should constantly fluctuate between 0.1v-0.8v the downstream one doesent really matter what it reads as long as it stays fairly constant. if the downstream sensor is copying the upstream one then the cat is not working.
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Mandrake
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Re: Saxo Mot fail- faulty lambda sensor?

Post by Mandrake »

isisalar wrote:Thanks for that Richard, I've checked the result and the first test was 1.044 the second was 1.036, limits being 0.97-1.03, apparently this indicates it's running rich.
I feel a service coming on, let's pray for dry weather.
Just so you don't get led astray Paul lambda values above 1.0 are LEAN not rich. :) Lambda = (air / fuel) / 14.7, (for petrol) so a lambda of 1.0 is stoichiometric with higher figures being lean and lower being rich.

I agree with wheeler too - don't waste time guessing, get it on a Lexia ASAP and check the function of the upstream oxygen sensor.

If you want a bit of background reading material on how lambda/oxygen sensors work, what goes wrong with them and how to test them I'd suggest either the tech notes at lambda power:

http://www.lambdapower.co.uk/technotes/techindex.asp" onclick="window.open(this.href);return false;

(fairly technical but good reading)

Or some of ScannerDanners videos relating to oxygen sensors:

http://www.youtube.com/scannerdanner" onclick="window.open(this.href);return false;

(more practical minded, but you'll need to search through his channel to find the oxygen sensor related ones, and there are quite a number)

A quick summary though - start the engine from cold and watch the upstream oxygen sensor, within a minute or two it should start switching high/low between at least 0.2 and 0.8 volts at about once per second. At a higher RPM it should increase to a couple of times a second.

If its sitting on 0.45 volts even after holding the engine at 2000 rpm for a minute then its probably dead. If it sits on 0.45 or only varies a small amount (like 0.4 to 0.6) even after a couple of minutes idling but starts switching the full range 0.2 to 0.8 after a minute of 2000 rpm the heater circuit may not be working causing it to rely on the exhaust gas to heat it instead of the internal heater element. (The oxygen sensor only provides a signal when above a certain temperature)

The oxygen sensor in my car at the moment has something wrong with the heater - it draws the correct current but it doesn't warm up properly at idle, only after the car has started driving, and that was a boxed new Bosch sensor... :roll:

I was getting a 1.02 lambda on my original sensor at the MOT, which was probably due to carbon contamination of the sensor tip, (it was well and truly choked with carbon) which makes the sensor sluggish and tend to give a "false rich" indication which causes the ECU to lean out the mixture in an attempt to compensate. On the new sensor I got 0.99 at the MOT but as mentioned I now have this problem with the sensor not heating up quickly at idle...so I'm going to have to replace it again... :roll:
Simon

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isisalar
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Re: Saxo Mot fail- faulty lambda sensor?

Post by isisalar »

Got the car on a Lexia today and indeed it is the 90 pound sensor from Jaystock that has failed, probably the day after it was fitted as that was when the EML came on.
So, need to get a new sensor fitted before the mot runs out on Wednesday. I want to get good quality. GSF or Eurocraparts most likely candidates due to time restraints, both seem to offer a lot of different opinions including it would seem a diy connector option, anyone got any recommendations?
I'm inclined towards the GSF premium one but it's an eye watering 130 quid!!!! Same as a Bosch one from the local factors. I'm pretty sure it would be genuine from them.
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
citronut
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Re: Saxo Mot fail- faulty lambda sensor?

Post by citronut »

the universal type can be a waste of time, as it is difficult to make a good/sound connection between the wire tails and the loped off original plug tails,
as the wire core is stainless steel,

i would also steer well clear of the E bunch as i have had a Bosch ( fake???? ) boxed Lambda sensor from them, that did not even switch in on the MOT re/test, even with my MOT man trying his hardest to get the thing up to temperature,

dont GSF do a cheaper sensor as that sound a bit steep for a Saxo one,

i have not had a problem with 99% of parts bought from GSF, and i use them a lot
Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years
citronut
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Re: Saxo Mot fail- faulty lambda sensor?

Post by citronut »

ps.
if you send me the last 8 digits of your chassis/VIN No. i will get you the OE part No., you can then do a goooogly search to see if there is anyone selling NOS= new old stock, of a genuine OE sensor
Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years
addo
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Post by addo »

There's another "cheat", you need to know which nose and which plug (pin configuration, whether two on two or four in a row, and colour).

Then you're able to choose from a plethora of sensors with leads longer than the "tailored" one they spec for your car. Who cares if it's a foot too long - just loop the wires discreetly.
isisalar
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Re: Saxo Mot fail- faulty lambda sensor?

Post by isisalar »

Thanks For the feedback chaps, First phone call tomorrow was going to be to the local Citroen parts distributor, Quickco, to check on the OE price. If you can help me there Malcolm I'll be very grateful. The Chassis no. is :- 57790811
Incidentally, for genuine parts I've found Quickco to be very good, certainly more knowledgeable, and cheaper, than the local Citroen dealer. They gave me a 10% discount, without asking, on a £60 sale and would probably do better for trade customers. They're effectively an independent main dealer parts department. Nationwide delivery too. http://www.quickco.co.uk/" onclick="window.open(this.href);return false;
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
addo
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Post by addo »

1628HN is the top sensor, they also suggest 1628HQ as a substitute (but it's dearer).

Lower sensor is 1628KY, or alternatively 1628HV (as above, substitute part is dearer).
isisalar
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Re: Saxo Mot fail- faulty lambda sensor?

Post by isisalar »

That's brilliant Addo, I'm now on the case.
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
citronut
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Re: Saxo Mot fail- faulty lambda sensor?

Post by citronut »

here is price and part No. for front and rear sensor's for your chassis No.

front, this is the one on top of the manifold
Part Number Description Quantity Price excl. VAT Price incl. VAT Total incl. VAT Selection
00001628HN OXYGEN PROBE 122.63 GBP 147.16 GBP 147.16 GBP

rear, this is the one after the cat
00001628KY OXYGEN PROBE 137.89 GBP 165.47 GBP 165.47 GBP

heres one gooogly result

http://www.lambdapower.co.uk/partsearch ... st=LC-9622" onclick="window.open(this.href);return false;

pm. sent
Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years
isisalar
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Re: Saxo Mot fail- faulty lambda sensor?

Post by isisalar »

Done a bit of searching and those part no's don't seem to match up with the vehicle I'm afraid.. The jist of it seems to be that there's various cheapies available on line for £30-40 some DIY some not, I've been warned off those. Eurocraparts have a cheapie at £66 and a Denso at £117, GSF have a standard one for £100 and a premium one at £130. Local factors £130 for Bosch/NGK. Could always go back to Jaystock for another £90 one and hope the failure was a one off, can't remember the make, but their stuff is normally good quality, it may well have been a Denso.
I normally go for the premium GSF stuff, how good or bad is the standard quality? When I had to get a MAF they warned me off the standard quality as a lot were returned, not so easy with a Lambda sensor.
Think I'll go round the local factors and see if I can negotiate a bulk deal together with the bottom ball joint and the bulbs. LOL.
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
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