What's to costly?? You can pick up a code reader at autojoke for $40, or add $100 to it and get a basic software package with cable to hook a laptop to the vehicle.
All depends on how in-depth you want to get with it.
I want something that will hook up and log the engine parameters on a test run to see what the heck is going on with my truck. Anyone got pros or cons to certain brands or what to look for or avoid?
Buddy has the AutoTap program, it will let you monitor just about every sensor on the vehicle. If I ever get the spare $$$ that's what I plan to purchase. unless of course someone cracks the ECM and actually produces an EFI live type program for Cummins :evil
check out autoenginuity. supposedly what factory tech schools use for training. I just ordered one today, one week ship time. I will post up thoughts when i get it and put it through its paces. 379.00 with one factory upgrade(ford,dodge,or chevy,choice of one). basic does obdII and CAN for 275.00.