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.