South Wales Volvos

The Stig · Posted: Tue Oct 30, 2007 4:49 pm Post subject: Lambda light but.............

Hope someone can help me on this problem . We recently bought a P reg 1997 855 , its a 2.5 20v manual

When the car was bought the lambda light was on , but the owner assured me that the light had been on for the 4 years he owned it . It never caused an issue at mot time .

On a recent local mini Volvo meet I was lucky to have another member who had a code reader to see exactly problem we had .
The code reader came back with a code number , and looking the number up it states the cat is weak . It also came up with another number which when read comes up with mixture slightly rich . According to the guy that read it thi may be caused by the cat being weak .

Now im a bit of a worrier thinking to myself will it fail on its next mot ( not due till march 08 ) so I have recently got my friendly garage to do an MOT emission test for me . It passed , so why on earth is the light on ?

This is what the printout says...........

FAST IDLE TEST

SPEED 2990 / MIN

CO 0.15 %VOL

HC 19 PPM

LAMBDA 1.00

NATURAL IDLE TEST

SPEED 850 / MIN

CO 0.14 % VOL

SUMARRY DETAILS

FAST IDLE TEST PASS

SPEED ( 2500-3000 ) PASS

CO (0.20 ) PASS

HC ( 200 ) PASS

LAMB ( 0.97 - 1.03 ) PASS

IDLE SPEED PASS

SPEED ( 450 - 1500 ) PASS

CO ( 0.30 ) PASS

EXHAUST OVERALL EMISSIONS TEST RESULT ( PASSED )

Are the above results well within the limits , would love to know from other members with the same engine your results just to compare

Colin · Posted: Wed Oct 31, 2007 1:35 am Post subject:

Mike - your emissions results are well within the limits.

As the light has been on for the last 4 years, and passed every MOT since, then whatever caused the fault code to appear is no longer a problem.
The fault may have been recorded if someone was tinkering with engine connectors while trying to find another fault. Possibly a spark plug or HT lead failed sending fuel down the exhaust. It could just be an erroneus reading that popped it up. There is no way of knowing what originally caused the fault codes.

I would rest easy - the 2 faults recorded are the only ones in 4 years.

The Stig · Posted: Wed Oct 31, 2007 10:57 am Post subject:

Ok just been going through the reciepts here , the last service states that " intake vac loose split @ manifold . The job was an advisery and wasnt done at the service according to the reciept .What this ?

Oh dear wish I knew what to look for , is this easilly spotted ? So this would cause light on ?
I find it so strange as the car drives perfectly normal .

Colin fancy having a look ?

bob13 · Posted: Wed Oct 31, 2007 11:00 am Post subject:

that split pipe will cause a fault and cock up the mixture, making it run rich or lean.

The Stig · Posted: Wed Oct 31, 2007 11:02 am Post subject:

Many thanks , it just looks a bugger to get to though....... http://volvospeed.com/Repair/vacuum_lines.php

bob13 · Posted: Wed Oct 31, 2007 11:05 am Post subject:

Not that bad, if you are passing this way i could have a look.

The Stig · Posted: Wed Oct 31, 2007 11:07 am Post subject:

Once the rain has stopped here I'll take a look , but it looks like I'm not going to be able to do it due to the location of the pipe .

Many thanks Bob

bob13 · Posted: Wed Oct 31, 2007 11:08 am Post subject:

sun is out here !

The Stig · Posted: Wed Oct 31, 2007 11:09 am Post subject:

drizzling here Bob , sun is trying to come out .

The Stig · Posted: Sat Nov 03, 2007 11:33 am Post subject:

Just an update to this , I replaced the split pipe but having no code reader myself I couldnt check to see if it cured the problem . The Lambda light did NOT go off after the fix , but the engine did seem to have a different noise if that makes sence .

Started car this morning for the normal drive to collect newspapers from the newsagent , and to my surprise the lambda light is NOT on .

How on earth has it gone off by itself ?

Colin · Posted: Sat Nov 03, 2007 10:23 pm Post subject:

Hmm, can't really answer that. It would seem however that the split pipe was holding the light on. I'm not entirely sure how the ECU handles faults. I thought that normally the fault is stored until reset.

Cally · Posted: Sat Nov 03, 2007 10:46 pm Post subject:

on some veichles if the fault is sorted then the problem light will go off but the fault will still be logged on the ecu but will have cleard itself for running if you understand what i mean Confused