Honda Insight fuel cut on ScangageII
 

I've had my ScangageII for a couple of weeks now and I was wondering why it shows a .2 ~ .3 Gallon per hour fuel flow when the Honda Insights L/100km gage is showing fuel cut when going downhill?

It's a bug. The SG doesn't report fuel cut under over-run accurately for all cars.

As I understand it from your interview, it's because OBDII doesn't actually define a way to report a fuel cut, and the engine keeps reporting a fuel pulse width -- not so much a Scangauge bug as it is an ECU bug.

On my Honda Fit I can recognize the fuel cut because the report goes to open loop; a future SG version might be able to use this, but it's complicated by the fact that the car reports a minimum throttle position of 13 or 14 rather than 0.

That's a better description, yes. (I didn't say whose bug it was :))

Calling it a bug is overstating things as well, since I don't even know if OBDII has standards that require them to specifically report fuel cut the same way across brands/models.

FYI, my car also reports minimum throttle pos of 13.

Which leads to another question. My throttle positon sensor reports from 8 to 92 for zero to full throttle. Is that another Scangage bug?

Not sure. Ask the ScanGauge people - Ron's good at answering mail. I'd be curious to hear what he says.

However, it sounds to me like just another non-standard OBDII practice.