2015 W204 1.6d Bluetec EGR issues

[776Lancer]

Hi all I'm new to to the forum (hello all) I've just got my first MB and I'm having a few issues. The main one is an intermittent EGR P049B fault.

So i have taken off the EGR expecting it to be blocked but it was very clean and the strainer was very clean as well, the car has just done 80K so far the fault has occurred twice and re set with no issues. I've read that this fault could also be the MAP or MAF sensor.

Has anyone has similar issues

 

[pcthrillrider2]

get a half tank of fuel, poor wynns extreme diesel cleaner in it and it will be fine like mine did

 

[776Lancer]

The EGR and strainer looked nice and clean. I'm unsure how injector cleaner will clean the EGR?

 

[776Lancer]

Hi all so after a trip to London (300mile around trip) and a few weeks of no issues today I had a lack of power (no engine light) and when I pulled over these are the faults I got which cleared ok and haven’t come back on since. Can anyone help out with what the possible cause is?

 

[markjay]

Seems like you have issues with the DPF. Either it's clogged, or the sensor has gone. You can try forced regen via iCarsoft or STAR, or you can try using DPF cleaner (Redex/Wynns etc).

 

[776Lancer]

if the DPF was blocked would this be a constant fault and not intermittent? I’m thinking it’s the DPF sensor but don’t have a OBD that’s good enough to check

 

[markjay]

if the DPF was blocked would this be a constant fault and not intermittent? I’m thinking it’s the DPF sensor but don’t have a OBD that’s good enough to check

There's no way around it, unfortunately, you'll need to get the car scanned on STAR, unless you want to play parts-darts....

 

[776Lancer]

so just had a look at the DPF sensor and found hairline cracks where the hose slides over and the plastic very brittle to the point it’s snapped off . So regardless a new sensor it is

 

[Tonygw]

Only use the genuine Merc parts, aftermarket parts will cause issues.

 

[776Lancer]

So replaced for a genuine sensor and all seems ok, checked for fault codes even though there was no fault light and found these codes

 

[BlackC55]

Its not likely to be an EGR fault. These suffer with the exhaust flaps seizing up giving the false EGR codes. Remember codes are only 1/2 the information.

 

[markjay]

A 'Pending' fault won't bring up the EML.

Try erasing the fault codes, see if they come back.

 

[776Lancer]

Hi so clears the fault then this fault came on. As for the EGR I’ve had that off and it was in surprisingly good condition no carbon and the valve moved with ease.

 

[markjay]

It seems that replacing the DPF sensor did resolve the issue?

Again, I strongly recommend STAR diagnostic and not getting dragged into a game of 'parts darts'.

 

[776Lancer]

I think it did but as a consequence the DPF now needs a clean

 

[776Lancer]

So fitted a new DPF sensor and cleaned the DPF and now I have a p2002 code

 

[776Lancer]

Update I’ve had a look at possible causes and seen that the back pressure sensor pipe can get blocked. Checked mine this morning and it was solid wit exhaust built.

Fingers crossed

 

[W1ghty]

Update I’ve had a look at possible causes and seen that the back pressure sensor pipe can get blocked. Checked mine this morning and it was solid wit exhaust built.

Fingers crossed

Good job buddy .

 

[776Lancer]

And we are back with faults again, so had a P2002 fault and then P049B fault. Had AA out to look and there was not faults in the ECU and that the car had done a Regen 9 miles ago and the pressure diff was both spot on which i could see for me self. My issue is that i had only travelled 9 miles from home so no way the car had regen

 

[BlackC55]

Have you looked at the exhaust flap like I suggested?