Ok I do not have that metal box...maybe the dealers here lost it after a service.....maybe have a look under there to see if the Inlet Manifold is bolted on firmly.
OK I can see and hear that first video you posted up. Sounds really sick....if it is not due to the injector CEL codes then I think you will need to pull off the head and see if anything is broken there. There are lots of good posts in the CRD Tech section on how to replace the timing belt...no real difference on the later USA models compared to our Export models.
Make sure the Alternator Clutch/de-coupler is working. These CRDs and the 2.4 Gasser have a one-way clutch on the alternator. Signs of it packing up are a red "rust" on the front plastic cover of the alternator. Remove the Serpentine belt and check the alternator pulley can only be turned in one direction...should freewheel in the other direction. Check the serpentine idler pulleys and tensioner pulley are in good shape. The crankshaft pulley I believe should have a rubber coupling on it as well...that engine of yours really jumps around!
MY GF smashed in the front-right of my Jeep when a tree jumped in front of her. Panelbeaters fixed up the damage but obviously drove the Jeep very low on coolant and blew up the head.
The Dealers fixed up the head, timing belt etc. but when I picked it up the engine had a bad vibration.
Turned out that they had mis-timed the counter-balancers under the crankshaft so check that out as well if you open up the engine.
The return fuel line will not affect performance just spill diesel on the engine but that is something you can fix up.
On the other side of the engine near to the airbox is a black solenoid. Has two small rubber hoses on it and a small plastic/paper filter dangling from it...two wires plugged into the connector.
That is the solenoid to open/close the EGR at the rear of the engine.
The ECM only complains if it senses that the wires going to the solenoid are open circuit or short circuit.
I have actually blocked off the one pipe with a small screw to disable the EGR....get slightly better performance. However if the EGR is actually stuck in the open position you will get bad performance.
Read up in the manuals how this solenoid/EGR works and how to check if it is working properly.
Make sure you definitely do not have a tear or hole in the CAC hoses going to the Intercooler up front.
These old Jeeps of ours have the possibility of the intercooler being filled up with oil from the PCV valve on the valve cover which pumps out oil unless you have the Provent or Elephant hose mod installed and also you may have cracks in the intercooler where the hose clamp on but this would only give you a small loss of performance....you can disconnect the hose at the intake manifold to check if there is a fairly strong air-flow coming out.
Our fixed-vane turbos use a form of Dump Valve located next to the turbo...read up on how that works.
Definitely clean the MAP sensor if you have not done so already.
Let me know how you are doing tracking down those error codes as regards using a meter to check voltages/resistance etc. at the ASD relay for instance as the procedures call out for all the error codes you are getting. You may need to get the Dealers to clear all the codes so that you can continue with a clean slate with any new codes. I suspect that the Injector codes could be the main issue!
The P0235 and P0110 codes were probably caused by you disconnecting the MAP sensor! I would concentrate on the Fuel Injector Codes and the Fuel Rail Pressure codes!
Check fuel and air filters are OK...I had a mouse set up a nice home in the air-box but this only affected the performance not the horrible noise your engine makes
Definitely log onto the ausjeepoffroad site as there are lots of owners of the Export CRDs there and some real experts such as "glend" who also posts up here on Lost sometimes.