Loud screeching noise on acceleration / load

[Bidja]

By the looks of your picture, U have stock exhaust.
IMO, think about fitting 3" exhaust sys (muffler / CAT) and while doing that remove the nuts that hold the EGR pipe flange up against exhaust manifold and fit a solid blanking plate and also do other end at the inlet manifold (then leave broken pipe in place). This mod (blocking EGR) is a good option and is part of the NADS installation that is beneficial for the engine performance and life. Part of the upgrade (NADS), U need a scan tool so to clear trouble codes as you will possible get a fault code P0401 - means that the engine computer has detected that the Exhaust Gas Recirculation (EGR) system flow is insufficient (resulting from blocking EGR assy). A scan tool is required and is a very useful diagnostic tool.

With larger exhaust sys and blocking EGR assy, consider installing "manual boost control" Dawes or Tillix and a needle valve. These mods will provide an improved run and controlled max boost @ say 16-16.5 psi and your EGTs will improve(reduce).
For boost management you need a boost gauge or say an UtraGauge (scan tool) that can provide boost measurement up to 22.3psi (would be adequate for stock engine or even for a ECU remap running boost of 22psi.

Suggest installing a Catch Can (ie: ProVent 200).
Gauges: Need EGT and Boost gauges. For the EGT gauge, the exhaust sys require to be fitted with a pyro probe and most provide this option.

The result would be good, something to think about.

[Flex]

How do you go about replacing the pipe as it's hard up against the firewall and the motor?

[threedogs]

Have a look in the mechanical section there might be a thread about it.
Maybe @Hodge may know. Have a think about blanking off the egr and investing
in a Scan gauge, a must for all CRD owners IMO, @Flex

[Bidja]

Remove intercooler and its frame, turbo heat shield, EGR assy_3 nuts @ exhaust manifold and 2 hx hd bolts at back of egr assy(radiator section)_refer your 2nd attachment @post 10 (radiator section not shown-it runs along side of eng on drivers side). Should be able to lift / jiggle upwards to remove the rear pipe section.
Might be best to get new exhaust fitted at shop and at same time get them to do EGR job (new pipe section or block both ends).

U will need to soak fasteners for a few days with a good anti-corrosive soak perpetrator prior to doing job.

May have to remove / drop dump pipe down out of the way to allow access to nuts @ exhaust manifold.
Will most likely split again after 100-150 thou kms, suggest you think about blocking both ends(refer suggestions post 11).