Jeep Liberty Diesel, Something Fishy?

I have a 2005 Jeep liberty w/ Diesel engine. With constant problems 2009.

They replaced EGR valve under code PO401 in October 2009 and again w/ a new Turbo in July 2011 (not sure of code). Currently has fault for low boost pressure. And they found very small leak from small crack in throttle body.
The Dealership says that because of the flow chart they are unable to determine if this is the primary problem until they replace throttle body.

Could the EGR, Turbo and this throttle body problem be related? Or does it relate to one of the other problems listed bellow?
I feel like I am chasing my tail.
How can I find a Diesel mechanic who works on small vehicles, but is not at the dealership?

Here is some of my 2005 Jeep liberty Diesel history.
October of 2009 Code PO 401: Changed EGR valve with improvement
November 2010 Code PO300 Changed fuel water separator and harness
April 2011. Found a Coost Pressure leak at hose Replaced Hose
July 2011 Faulty turbo and EGR valve Replaced EGR valve, tube removed inner cooler and sent for cleaning, reinstalled evac and recharged. (Dealership took on some financial responsibility for Turbo)
October 2011 They wrote “Has fault for low boost pressure. Found very small leak from small crack in throttle body"

I was unaware that Diesel engines had a “Throttle Body”…Usually, their air intakes are unrestricted. Engine RPM and power output are controlled solely by varying the fuel injected into the engine.

When small, high-output turbo-charged diesels run up against stringent emissions regulations, these are the kind of problems you can expect…If you are not subject to emissions testing (other than a simple visual check for smoke) I would disconnect and block off the EGR system and if the vehicle operates satisfactorily, stop worrying about it and drive on…

Thinking about this, the “throttle body” may be the point where the exhaust gas is injected back into the engine and this may be combined with a turbo “waste gate” , a device to limit boost pressure…

If you intend to keep this vehicle, YOU may need to educate yourself as the the finer points of its design and develop the skills necessary to maintain it yourself…

Thank you. Your right I need to educate myself.

Today, most people simply can not afford to pay professionals to maintain and service vehicles that develop difficult to find and isolate problems…Obtain a Factory Service Manual or even a condensed aftermarket shop manual and learn how your engine operates and is controlled…The “crack” in the throttle can probably be repaired with an industrial epoxy like J-B Weld but don’t expect a dealership or professional mechanic to do that…YOU will need to develop those skills…