Lambda light (now you see me, now you don't!)

A couple of weeks ago (whilst in stopped traffic) the Lambda light came on. My initial reaction was to panic but as there was no noticible loss in performance I tried not to worry too much. A week or so later I got called out at 2am and had to drive into work (nice). Whilst en-route through a nice forest road I noticed that the light had gone out! I suspected this was due to the lovely cold, dense air being sucked in but my celebrations were premature, two days later it was back and has remained on since. I've even tried getting up early to try and get colder air in but to no avail.

I suspected it was the CAT but it passed the MOT emmissions tests with the light on (with lower readings than last year!)

My questions are these......
1. What exactly does the Lambda system monitor?
2. Is my CAT knackered?
3. What else could be causing this problem?
4. How much (roughly) to get it looked at?

Any assistance with this would be greatly appreciated.

Is there a meeting planned soon and if so when/where as I'd like to meet up with some other T5 nuts.

Thanks,

Adam
'94 855 T5

[rstrang]

Hi Adam,

First place to check is here:

http://www.volvospeed.com/Repair/vacuum_lines.htm

Hope it helps.

Richard

[Chris_Rogers]

First thing read the fault code,

The site mentioned above will tell you how.

Then post the code here for further advice.

Chaps,

Firstly, thanks for 'encouraging' me to dig a bit deeper. I had look at the codes and got the following.......

2-2-5 'Air con pressure sensor signal weak or absent'
2-3-2 'Long term fuel mixture too weak or too rich at idle'

After reading I reset the codes and sure enought the Lambda light went out. It has come on again this morning though after about 20 minutes.

The 2-2-5 is easy to explain as the car has aircon but it is not a standard Volvo fit so may not be connected in the same way.

The 2-3-2 is another story. Anyone got any ideas as to what could be the cause of this (and how much the bits are!). I haven't checked the codes since the light came on but will do so tonight (suspect it will be the same as yesterday though). I also haven't had a chance to check the vacuum lines (elbows) yet but will have a look at the weekend.

Once again, any input gratefully accepted.

Cheers,

Adam
'94 850 T5

[rstrang]

Adam,

Check those elbows...especially the one on the inlet manifold behind the power steering pump it's the first picture on the link above.

If it is that one then parts are cheap, but changing it is an absolute b*$%**d.


Richard

Thanks for that Richard. I'll check them over the weekend and post back my findings.

May see some of you at Gaydon at the weekend.

Adam
'94 850 T5

[Chris_Rogers]

Agree the elbow behind the PS pump.

Changed mine recently, a bit of a challenge.

I did mine by removing the top radiator hose to improve access, levering the old elbow and clip off the manifold with a long screwdriver. Carefully used a craft knife to slit the elbow lengthways and peel off the plastic hose.
I used silicone grease to lub all the parts, then pushed the new elbow onto the plastic pipe then fitted the clip onto the new elbow and pushed the elbow, complete with clip, onto the manifold nipple by hand. Refit the top hose and refil.