Hi Folks. HELP PLEASE!

I Have owned my two owner 2008 Discovery 3 tdv6 xs manual Gearbox for 3 years and generally has been a good solid reliable runner, when it runs I lvoe it--right now not in love!! - 128k on clock FSH new MOT, repairs of late (4 months) I have:
1. New Clutch - corrected slipped and EPB warning
2. 2 x New EGR (one stuck one sheared)
3. Replaced Wiring Harness
4. Service and new bushes

combination of lockdown and service reparis means I have seen little of this car

I recived it back a week ago and yesterday it dropped back into Limp Mode
Limp mode will not clear by restarting engine multiple times but only if I leave car overnight then it will clear for one short trip before returning.(perhaps after engine warms up?)
I got a `cheap and I know i shouldnt but was only one that would arrive next day' reader to reset code/EML after limp dropped, now it has come back and nothing will clear it--code clears--then comes back
reader states EGR Control Circuit P0403 error

I am not a great DIY mechanic and it is bank holiday so not much help out there if this is an easy fix?? I have read around but would be interested to get best guess here:
1. Battery? using the `secret menu' it shows 12.5v off and 13.5v driving
2. Turbo Actuator? ? engine runs and revs fine (obviosuly doesnt rev in limp mode), no issue with engine idle, no misfiring etc..
3. EGR solenoid? but thought this was sorted by garage when they did egr and had this fault before--but not sure if it was changed
4. I read on one link somewhere that i havent found since that having changed the EGR mabe ECU needs reprogramming at LR Dealer????
5. Anyone go better ideas? thought son what order I shoudl perhaps look at these and advice on hwo to looka t fix if possible
Big asks I know....

finding the right thing to fix and fixing it is not my forte but frankly prepared ot try anything right now--any help much appreciated thanks

 

First off being a US based site the TDV6 is not sold in this market so you wont get much assistance for it, You only have the generic code which makes it hard to narrow down but a quick google says that you still have an EGR fault so that is possibly leftover from before they were replaced or 1 is faulty.
Were they definitely new and genuine or aftermarket ?, i would have fitted blanking plates and saved some cash.