I am looking at buying a used RX8, and I am bringing my OBD-II scanner with. However, it would be good to have a baseline to go against. Anybody have their readings off a well running, unmodded car?

 

What is it you expect to get from the OBD ?

 

Oh, things like idle speed before and after the test drive, if its running rich or lean, ability to hold a voltage, intake temps, O2 levels, etc. Obviously testing for a stable idle is easy, but some of the others would be meaningless numbers without something to compare against.

 

Its irrelevant. At idle AFRs should run as close as possible to stoich'. Intake temps should be a few degrees above ambient after a good long cruise.

My take on it anyway.

 

So, if you are of the opinion that monitoring an engine under test will not yield anything useful, I'm curious to hear what you think the meaningful use of a scanner is.

 

Irrelevant was in relation to the "baseline" part. If you really want to know the "baseline of your car, then pull the calibration and see what its supposed to be doing.