Should I even bother?
 

I'm a handy guy, I've fixed many a car in my day. Even with limited resources and minimal reference I've been able to diagnose a couple of the issues I've run into with my R.

Problem is, I can never exactly pin-point THE issue. Usually, with past vehicles, I'd have an issue, do some reading, diagnose the EXACT problem, troubleshoot to confirm, then DIY fix it myself or take it in and EXPLAIN the problem and solution to the mechanics and viola they fix, I'm done.

The new paradigm I have begrudgingly accepted is; I have a problem, search the forums/google for anyone that may have some similar problem, find almost nothing, give up, take it to the MB dealership for diagnosis ($150-180/hr), hope my warranty will cover whatever they find, if I'm lucky pay only $100 co-pay, if not, oh well, it's a Mercedes.

I have no idea if the mechanics would even listen if I had the answers before they started poking around. So I guess I'm asking, should I buy an ODBII scanner? Will it actually point me in the right direction if I decided to troubleshoot and DIY myself? Or is this just another one of lifes pointless, pissing in the wind, exercises?

Whats the problem? those OBD2 scanners wont always diagnose all the systems.

Currently I'm confronted with a "P0452 EVAP system pressure sensor switch low input" that I believe may have been triggered partially because I filled the tank while the car was running. The check engine light came on, stayed on that day and the next day it was off.

Now it's back on and I just swung by Advance auto to get that code. The car seems fine, but you know, one should clear these things up in case more major things happen.