I've been a member of this forum before in the past and I do come on here and read every now and then, but I've re signed up as I need Some help.

I have a 56 plate fiesta Mk6 (facelift) 1.6TDCI and been having some of the dreaded and (by the looks of it) common EGR issues.

Car was running ok, until engine light came on and lost boost. Would still drive fine, but no turbo / boost. Turning engine off and back on again would give me boost again for 10 mins or so, before engine light would come back on and boost would disappear. Checked turbo and boost solenoid and all seemed fine. Did diagnostics and it came back with the old p042f - egr stuck closed. 

Temporary 'fixed' problem by unplugging electrical connector to egr. It would still throw up a P0405 - egr circuit low code after an hour or so of driving, but at least I get to use my turbo.

I removed and inspected the egr expecting it to be all crudded up or stuck, and although it was a bit dirty, mechanically it wasn't too bad and the valve could defiantly open and close. 

I stripped down the motor side down and the contacts seemed a bit worn so I decided to swap out the EGR and cooler as one.

I gone a second hand one of a working car, gave it a bit of a clean and fitted it. Started the car and after a little bit got the original P042F - EGR stuck closed fault and no boost. So now I'm back to driving around with the EGR disconnected.

Any advice please how I can fix this? I'm now thinking it's not the EGR but another problem. I've seen posts on here about testing the wiring and connector, as well as setting some values in fordscan.

Anyone got any more details on this?

Cheers in advance

Hey Adam, months back when I got my mk6.5 fiesta zetec s 1.6 TDCi it was left on the driveway for 2 months and was driven in and out the garage until my insurance renewal came up for my previous car. At one point the engine light came on and the code was to do with the Egr. Try deleting the code with the diagnostic tool as I deleted the code and it never came up since. You can see from there then and probably clean out the EGR or blank it. 

I opened it up and cleaned the inside of it and I definitely noticed the pin which the motor moves I was able to move with very little pressure after cleaning it

I would say it must be an electrical issue as a guess as if you blank the egr on the 1.6 you have a noticable differwnce in power a lot more

Have a similar problem with an '08 1.6tdci, have changed egr valve but still getting intermittant fault code P042F. How does the ecu "know" that the egr is stuck in closed position? Is there position feedback signal from egr valve or is it looking at pressure sensors/other sensors? Seems to me that problem is a sensor giving duff reading which ecu then interprets as egr failed to open. If this is correct, which sensor and where is it located? Does anyone have or know where I can obtain a electrical circuit diagram for the engine management system? Thanks in advance, Phil.