Ah, I misunderstood what you were saying, I thought you were telling me that the computer I installed in the compuer was a bad idea.
And yeah, the OBD-II is for displaying in-depth diagnostic data about the car. It's super keen, and has already paid for itself. A scamming mechanic told me the check engine light came on during a smog check and that automatically failed it, and tried to get me to pay $150 for them to read the code off the computer. When I said that I had my own reader, they said 'no, you need a $15k dollar reader like we have' and I said 'Nope, actually I just need an OBD-II reader. I have the software too, let me go look it up" and they suddenly got really evasive, saying that they couldn't use the results from whatever test I did, etc, etc. I left, looked it up, and there were no freeze frames stored (as is standard for GMs), no log of the light being turned on, etc. I called them as a courtesy before writing a letter to the Better Business Bureau to let them know what happened, and they were all over it saying 'we must have made a mistake, let us run the smog test again for free' and I told them I didn't want them touching my car again.
After this longest of run-on sentences, I took the car elsewhere where it smog-passed with flying colors.
