W203 C220 CDI DPF Issue

[TheMOTman]

I am pulling my piggin hair out now... Fault codes (amongst others) 2082-8 B28/8 DPF Sensor Plausibility due to defective hose line.

This is putting on the MIL and hence limp mode. I replaced the B28/8 DPF sensor with the latest one, checked rubber hoses were fine. Cleaned DPF & Forced Regen - performance improved but still went to limp. I replaced the DPF with a brand new one today - No joy - Goes back to limp mode after 10-15 mins of driving. Fault codes can be cleared and performance is fine but always goes back to limp after a short drive.

New codes today after fitting new DPF are 2084-2 DPF flow monitoring of air mass. The air mass is too small.

and 2073-8 Check G3/2 O2 sensor upstream of KAT Plausibility.

This is the first time I have seen these two latest codes.

Any pointers would be much appreciated.

 

[BlackC55]

Blocked CAT?

Have you a Star?

 

[TheMOTman]

Thanks for reply. I wondered about a blocked cat although I thought the diagnostics would have pulled a code from it, I have another cat so might change it as well. Pig of a job on these though. I don't use STAR but my diagnostics platform is excellent and covers MB no problems.

 

[TheMOTman]

I am actually discounting the CAT as there is no performance issue when the fault codes are cleared. it goes like a scalded cat for 10 mins at least... if the CAT was blocked the power would be well down regardless. Looks like I will have to backprobe the electrics to see if there is a break in the DPF sensor wiring.