Poor Performance & EML - Suspect DPF and/or Exhaust Pressure Sensor - Part #'s Needed Please

[sjuggins]

Looking for some part numbers please.

I've recently acquired a diesel (2009 W204 C220 CDi) runabout with some issues, I got it very cheap as I knew there were some faults...

After doing my research and scanning for faults (of which I get several) I suspect either the DPF Sensor and/or the Exhaust/Manifold Pressure Sensor could be at fault (if there is one) based on similar problems of others. Checking diagrams I can't find the Manifold Pressure Sensor, only a Boost Pressure Sensor which is situated around the EGR.

When I scan the car with live data, rev the car to around 3-3.5k RPM, the exhaust back pressure remains at 1bar and the boot pressure (which I presume to be DPF pressure?) only rises from around 1.050 hPa to around 1.150 hpa.

I'm investigating the EGR and Manifold/Flaps over the weekend but want to try and get parts ordered ahead of time. I've noticed some quite suspect wiring mods around the EGR connector so suspect it might have had the emulator/resistor tweak but until I go through it properly I'm guessing.

Can anybody please confirm the correct parts. I believe the Boost Sensor part is A0061539928 and DPF Sensor part is A6429050100.
Can't for the life of me see/find the Manifold Pressure Sensor - is there one?

Thanks!

 

[onefortheroad]

Ebps should rise tbh. 1 bar is atmospheric pressure.

Dpf pressure sensor should be as close to zero as possible.

 

[sjuggins]

Managed to fix all the issues and it was all wiring related, had to repair a damaged part of the loom and several connectors. Car drives great now all values are reading properly except for the Exhaust back pressure which remains fixed at 1bar. Thinking it could need the DPF cleaning out as the tailpipe is really sooty? Will see if it regens itself over the next few days and if not perhaps change sensor?

 

[w204benz]

I believe the Exhaust back pressure reading is just used to avoid overstressing the turbo - nothing to do with the DPF.
For the DPF, you need to look for the differential pressure reading. Normally, if it's below 10 mbar at idle, the DPF is usually fine.

But if you're saying the tailpipe is really sooty - that is a pretty good indication that the DPF is cracked. Unfortunately, if that is the case, cleaning it would be a waste of time and money. It may have a faulty sensor too, but not much point in swapping it out first if it needs a new DPF.