If you're able to go about wrenching on it yourself/have the time and tools, I'd say save the money on the tuneup and do the oil change yourself (~$$80 in oil and filters) - Mobil One synthetic 5W-40 is sold in gallons at Walmart for like $26/gallon (it's the only reason I'll walk into that place).
You can easily look at fluids and see if any of them need to be topped off, except for the Tranny fluid, which you (stupidly) need to buy the dipstick for, and buy the little amount that you might need.
The codes will definitely need to be diagnosed before they'll pass the smog, and some places will read them for you for about $20-$30. Or find a local with a unit to do it for you.
The best option though, and why I say save the money is that for $200 more than your tuneup, you can get the Green Diesel Engineering tune, which MAY JUST save you from not being able to pass smog. Many Sprinters get failed for EGR issues that are $$$$$ to fix, and the GDE tune disables it, as well as gives you a code reader with the tune so that you can read and clear your own codes.
That, I'll submit, would be the best use of your $$$$...