Euro4 D5 / 2.4D DPF or Sensor Issue ?

[graemedench]

OK I've checked all the wires to the Heated oxygen sensor and given them a good shake at the same time and they are all fine. The fuse for it was a little corroded so I stuck a new one in. I then ran a test, Note DPF not attached nor is the DPF pressure sensor or the DPF temperature sensor hence codes. And the exhaust venting straight after the CAT. The other codes show the AQS sensor issue and because I have an aftermarket head unit installed just now.

The test was just under 2 minutes and the pictures should be sequential then a re scan at the end.

The Lambda basically didn't respond for around a minute then started giving the values you see. The exhaust seemed to have excessive soot the whole time but did vary.

Please correct me if I'm wrongly assuming but the Lambda sensor looks broken? Possibly the cause of the issues ?

[skyship007]

Originally Posted by graemedench

Well I thought I'd try get a air readings on the intake side while the heated oxygen sensor was reading strangely however as you can see from the pics, it was reading fine grrr. Shook the wires about but couldn't get it to fault or anything. I've taken it out anyway, I will try some meter tests on my bench with it and also have a good check of the cables going to the ECU connector.

Skyship any input is always welcome you'll see through the previous posts we've established the DPF is clogged but now trying to determine why it clogged. hence just do a a basic injector test, that along with rpm and correction figures give a good indication if things are at least not too far wrong. This way when it gets replaced / repaired it wont instantly clog up again. Also I have a Vida software etc so I can get codes and senor values etc.

5cilinder has been extremely patient and methodical trying to work through this with me even though I've been a bit very annoying and missing out useful information at times (not on propose)

A new pressure sensor is definitely required also possibly a heated oxygen sensor (maybe cabling repair we'll see)

My intention is to get it sorted and then sold but I'd much rather sell it working correctly.

Obviously replacing the sensor and getting the codes read will help, but DPF's do block with engine oil ash. If the injectors are gummed or have blown tips it will not log a fault code, so once they have been cleared if you are selling your pride and joy, I would try an idle flush oil additive (Castrol, Amsoil or Liqui Moly all make real good ones) and low Saps (Zinc based anti wear additives) fairly thick but cheap FS oil (Shell Ultra 0w40 DPF approved, which might mean a C3) and half a can of LM stop leak.

If the oil has been overfilled OR the CCV has blocked (Common if you run too high an oil level and use cheap Dino based oil), it will foul the DPF into a fault code fairly quickly.

[5cilinder]

Interesting!
Your airmass and egrvalve positions are as they should under those circumstances but the lamda reading is way out of line far too low and far to high
Now besides of the lambda reading i now your real lambda is ok because of the airmass and egrvalve position.
The sooting is therefore surprising, injectors seem to be good and enough air (try also a injector cleaning with an additive that wont hurt anyway)

did you sync your faultcodes? im surprised to see no o2 sensor fault
And try to get live data from the o2 sensor if it fluctuates like the lamdareading you need to replace it (if the wiring is ok)

[graemedench]

Hi
Its hard to tell I guess how bad the soot is It could be that its hanging about under the car and coming out in small batches making it look worse than it is, It seems a little more than my wife's euro 3, but then its going through a complete exhaust system on hers ! its certainly less than when she floors in and leaves a smoke screen lol !

I can only seem to get the live Lambda in Vida (I presume maybe wrongly that its from the O2 sensor?) I'll try my handheld scanner and see if it can read the O2 directly.

I did re-scan the car at the end again and it didn't show the O2 sensor error, But I will go scan again and see whats there.

Looking like the fix list maybe O2 sensor, DPF sensor, DPF / Cleaning, Oil change and careful 3/4 fill

Thanks again for all your help,

[5cilinder]

Is there under the ecm tab in vida no live data for o2/voltage? im not sure myself
in the row where you got your air mass and pressures etc

Well its or dpf sensor or dpf cleaning if you want to safe money start with one and see if it resolves both! if not no problem than the other as well

[graemedench]

Hi

No O2 / voltage, double checked and my other scanner is useless with the Volvo, No fault code about the sensor either! Interesting I gave it another quick run it takes about 1 min before it reads the the Lambda (maybe gives it time to heat ? ) this time I got :-

2.38 at 713rpm
1.82 at 1971rpm
1.9 at 2337rpm
2.45 at 736rpm

I think this o2 is just giving random non-sense. I can get a used on for £20 so I'll pitch for that.

[5cilinder]

Those lambda figures seems to be about right

[5cilinder]

About your comment of heating , i think ur right. ill check it with my torque but you could be right about that it takes some time to get the correct lamda reading
I slightly recall that after starting my engine the lamdareadout on my torque stays at max level for a minute or so
I ll check that and report it back

[graemedench]

Just an update .. Waiting on new sensors and cleaning out the DPF at the same time. Got some DPF flush stuff you leave to soak in then flush out.

In the mean time taking the stereo out (putting back to stock) and getting the car ready for sale.

[5cilinder]

Why is that people buying broken things fix them up and sell them
If everything is fixed your in better shape then a buying a new used car with all possible hidden issues