BAVBMW
you (and al gore) are obviosly passionate about your craft. I get it and appreciate your advice. I would appreciate your professional and technical advice please - although i'm an avid diy'er. I let my local redwood city mb dealship service my 2000ml430 with 80k miles. after a recent $2100 B-service, plus fuel filter/lines and MAS 2 weeks ago, the truck needed a tow back to the dealership for a $600 Egr (according to mb) the next day. The egr lasted a day, check engine light along with significant stuttering and hesitation followed. now with GREAT apprehension, I'm bringing the truck back to the mb dealership (they know I'm really frurstrated and broke). the service manager says he thinks I may need a cps however he has not
diagnosed the problem. my cheap scanner is giving me p0170,po173 and po0300's. appreciate your advice regarding:

1) how do I deal with the mb dealership and what recoarse do I have.?what I mean by that is, the car was fully functional with no problems until i brought it to mb. at what point (if ever) does the dealship take accountability for what I believe is misdiagnosis that lead to excessive costs leaving me with an unsafe and unreliable car?

2) did replacing the fuel filter and line upgrade throw off the balance of the other systems - dumb question i know but I'm wondering why the fuel delivery upgrade was required and why I was required to pay for it if it was in fact a design flaw...