I have a very primitive logging app that uses dynamic PIDs, pretty much how kur4o described, it's included in the PCM Hammer zip file. There are 2 big issues with it right now thoug

1) It does not (yet) have any UI for choosing parameters to log, so you have to edit an XML file to change parameters.

2) It can easily log standard PIDs for any GenIII GM vehicle (well, if editing XML is "easy") but a lot of the parameters that are interesting for logging need to be reverse-engineered for each different OS. The values exist in RAM but it takes work to find the address and the formula to convert the value to units that make sense.

I've been working on finding stuff in 12593358 because it's what came with my car, and I didn't know any better. :)

If anyone out there is familiar with IDA Pro, or is looking to get started, I think the world would really appreciate having logging parameters and addresses for:
- 12212156, because that particular P01 operating system is available with every combination of DBW/DBC and MT/AT.
- 12216125, because that particular P01 supports flexfuel (not sure which throttles or transmissions it supports, though)
- 12587603, because that P59 operating system supports flexfuel and all combinations of throttles, transmissions.

Rather than disassembling every OS GM ever made, I think we should focus on those three. I'm going to switch my car over to a P59 with 12587603 this fall.