DPFE sensor erratic readings after DPF cleaning, new EGR valve stuck closed

[tallrob]

Hi all, I need some help figuring out what I've done to my car after my second round of P242F DPF dealings with my 2007 S-Max 2.0 tdci (WA6)

A couple months ago I got the dreaded P242F DTC along with limp mode. I got another DTC P1335 telling me the EGR valve was stuck open, so I cleaned the EGR valve, did the MAF sensor trick and reset the code, followed by a long drive to activate a regeneration. It all worked out and the car was back to normal.

About three weeks ago I started getting the EGR code again, so I started monitoring the DPFE pressure. Over the course of the next week it steadily rose, but would not start a regeneration. I tried taking it on several long trips while monitoring the data, and it seemed to try a regen several times, but stopped just below 500º, and registered a failed regen attempt. Last week I got the P242F and P2463 DTCs again. 

I couldn't reset it using the MAF trick, so this time I decided to remove the DPF and wash it with soap and water. It took a while but I got the water running clear and dried it for about an hour with a shop vac blowing in reverse. Just to be thorough, I also replaced the EGR valve, MAF sensor, DPFE sensor and air filter, cleaned the throttle body and changed the oil. I expected that to cover just about all the bases. I reset the EGR learned values and DPFE learned values and took it for a test drive.

The first thing I noticed was the DP_DPF pressure was extremely erratic, going from 0.9 to 25.0 kPa with values all over the place in a non-linear fashion. Also, the EGR valve appears to be always closed: EGRTP_V 4.46v EGRVP_V 1.00v EGR_TV 10.98% EGRVR 0.00% EGR_ERR -100% EGR_PCT 0.00% When I pull the plug on the MAF, the EGR values change for a moment, so the valve is functioning. It's just not changing at all while driving, whether the engine is cold or warm. 

After driving for about 45 minutes on the highway, the DPF did a regen, climbing to almost 700º. The DPFE sensor however is still erratic so I have no way of knowing what the actual pressure is. I'm pretty sure this is still the original DPF after 240,000km, so I'm ordering a new one which should arrive soon. However I'd like to figure out the issue with the EGR and DPFE sensor before installing it.

I checked the turbo lines and everything looks pretty good. I'm going to replace the DPFE hoses and perhaps send this sensor back for exchange. I'll put the old sensor back tomorrow and see if the pressure reading stabilizes. I also thought of cleaning the intake manifold but at this point I'm just shooting in the dark.