DPF issues and limp mode, w203 cdi

[Theo00]

Hello everybody, I'm new on the forum and I hope somebody can help.
My w203 2005 200 cdi has been having some issues lately. It throws the check engine light and when scanned with the icarsoft device it shows the 3 codes attached as pictures. The issue is intermittent and mostly comes when the tank is over half full which leads me to believe the car is trying to do a dpf regen. If the codes are cleared the car drives normally and has full boost for the next hours. When the issue comes back the car goes into limp mode sometimes without throwing the EML, and sometimes the EML comes on but the car doesn't go in limp mode, this makes me think that I'm dealing with 2 different problems here. Can anybody point me in the right direction?
The car has already got the DPF sensor replaced but no luck. I also undid the hoses and made sure they weren't blocked, and also made sure the connecting points where the hoses mount to the exhaust weren't blocked and cleaned them but after driving for a bit the fault code came back. Also checked the live data of the dpf sensor while driving and with the revs below 2k it showed zero or -1. Above 2k it went up to 3 or 4. The values were checked with the icarsoft v2.0 and the unit is hPa in case somebody is interested. Any clues to what I should check next? I also tried gently blowing into the sensor while plugged in and the values were changing, which leads me to believe the sensor is fine.
Another interesting thing I noticed is that the ash content is at 0% load state of the filter is at 105% which leads me to belive that the car maybe has had the dpf removed from the previous owner. This could also be the reason why the sensor reads 0 as pressure difference since the 2 hoses connect before and after the dpf. Can anybody shed some light on this?
Thanks

Edit Quote

 

[m80]

I find the last description implausible, how would it know?

I had the cabling to the DP sensor go brittle and break. It was insecure and the exhaust heat affected it. I soldered in a patch and that cured it. Maybe yours is intermittent, maybe it's a red herring. Could be worth a look.

 

[Theo00]

I find the last description implausible, how would it know?

I had the cabling to the DP sensor go brittle and break. It was insecure and the exhaust heat affected it. I soldered in a patch and that cured it. Maybe yours is intermittent, maybe it's a red herring. Could be worth a look.

Well since the sensor measures the pressure difference before and after the filter and it reads zero, it means that there isn't anything in between. The cabling is fine, checked the live data while driving and there aren't any intermittent values.
Is there a way except for looking for weldings to know if the dpf has been removed?

 

[m80]

A DPF can be removed and gutted, with no external evidence.
Remove and you would see nowt in there if gutted.

But the ECU would need to be remapped or it would never have run w/o the EML. I'm assuming it has been ok in your ownership.

Star / Xsentry is favourite here, maybe it would show live readings outside parameters.

 

[HITECH]

Have you tried a forced re-generation on the DPF. There is no such thing as YOU CAN NOT FORCE RE-GENERATE a dpf because.......... one of the only reasons a forced regen will fail is if there is some kind of other turbo intake hose leak fault or a MAF fault which throws a fault code and chucks on the engine managemet light fault resulting in a regen cancelled and failed. Who replaced the DPF pressure sensor and how much was it it was not a mercedes sensor. It appears you have a a DPF, MAF & EGR fault combined.
1. check all Turbo hoses, intake hoses, thicker hoses.
2. clear all codes THEN unplug your mass airflow connector and drive your car for 24hrs to see what differences if any there is. (EML light will come on, ignore it)
3. Can you get EGR simulator box done on your engine ? ( gets rid of the crappy EGR system ) look into it....
4. If it was a cheapo new aftermarket DPF pressure sensor then that was a very BAD IDEA.

 

[OneForTheRoad]

Well since the sensor measures the pressure difference before and after the filter and it reads zero, it means that there isn't anything in between. The cabling is fine, checked the live data while driving and there aren't any intermittent values.
Is there a way except for looking for weldings to know if the dpf has been removed?

Tap it with a screwdriver, empty vessels make the most noise n all that .

 

[Theo00]

As suspected the dpf and the cat was indeed removed. Tried the screwdriver trick and it sounded like an empty shell. I also removed the dpf to look at the insides to be 100% and it was absolutely emtpy. There were no welding marks but my cars dpf was attached together by screws, so you didn't need to cut it open, you could just uncrew it and it would fall apparent. Still, your feedbacks are appreciated.

 

[WilliamParsons]

As suspected the dpf and the cat was indeed removed. Tried the screwdriver trick and it sounded like an empty shell. I also removed the dpf to look at the insides to be 100% and it was absolutely emtpy. There were no welding marks but my cars dpf was attached together by screws, so you didn't need to cut it open, you could just uncrew it and it would fall apparent. Still, your feedbacks are appreciated.

It's clear that both the DPF and catalytic converter were removed from your car, and you've verified this by checking the insides and finding them empty. Your description of the DPF being attached with screws rather than welding marks is helpful information. Thank you for sharing your feedback.

 

[HITECH]

As suspected the dpf and the cat was indeed removed. Tried the screwdriver trick and it sounded like an empty shell. I also removed the dpf to look at the insides to be 100% and it was absolutely emtpy. There were no welding marks but my cars dpf was attached together by screws, so you didn't need to cut it open, you could just uncrew it and it would fall apparent. Still, your feedbacks are appreciated.

It would be good to see a picture bud if you can.

 

[DanE350cdi]

I had this problem with my Transit van, turned out to be a faulty fuel vaporiser which couldn't perform a regen. Once changed for a new one it was fine. Not sure if Mercedes use this method but worth looking into. Its a silly idea on the ford as it blocks up easily with carbon and it is commonly overlooked.

 

[Theo00]

It's clear that both the DPF and catalytic converter were removed from your car, and you've verified this by checking the insides and finding them empty. Your description of the DPF being attached with screws rather than welding marks is helpful information. Thank you for sharing your feedback.

I also was quite certain that that was the case since the dpf sensor was good and it was the only logical explanation for those readins.

It would be good to see a picture bud if you can.

Unfortunately I didn't take any but it looks exactly like this picture I found online.

I had this problem with my Transit van, turned out to be a faulty fuel vaporiser which couldn't perform a regen. Once changed for a new one it was fine. Not sure if Mercedes use this method but worth looking into. Its a silly idea on the ford as it blocks up easily with carbon and it is commonly overlooked.

It can't be something else since the dpf and cat is physically missing and this is beeing picked up by the sensors.

 

[Theo00]

Have you tried a forced re-generation on the DPF. There is no such thing as YOU CAN NOT FORCE RE-GENERATE a dpf because.......... one of the only reasons a forced regen will fail is if there is some kind of other turbo intake hose leak fault or a MAF fault which throws a fault code and chucks on the engine managemet light fault resulting in a regen cancelled and failed. Who replaced the DPF pressure sensor and how much was it it was not a mercedes sensor. It appears you have a a DPF, MAF & EGR fault combined.
1. check all Turbo hoses, intake hoses, thicker hoses.
2. clear all codes THEN unplug your mass airflow connector and drive your car for 24hrs to see what differences if any there is. (EML light will come on, ignore it)
3. Can you get EGR simulator box done on your engine ? ( gets rid of the crappy EGR system ) look into it....
4. If it was a cheapo new aftermarket DPF pressure sensor then that was a very BAD IDEA.

The manual regen showed as complete right after I pressed start because the ash content would always show 0 I suppose since there was no dpf installed.