CO metering at exhaust, Prius 2012

I want to anecdotally check with those who got experience with CO readings if these values are fairly "normal".

I'm using a toptes CT 580.I wamed the car for a while, until it got warm inside, the air temp was around -8C.

When I began reading, I was surprised to get values between 10-30ppm, regardless if I was a few inches away or at tailpipe. Eventually, I got some 50-120ppm readings as the engine went through a few cycles of ICE engine going on/off.





Then I caught it, right as a new ICE engine cycle was starting and I got an initial 450ish ppm reading that tapered off to those familiar values above.



I didn't know what to expect. I deduct that combustion is poor as the engine restarts and then quickly becomes more efficient.

I've been burning some maple toothpicks, for reference, and I got around 200ppm sharply dropping to 50ppm then tapering to 0-10ppm.