Yeah, I'd have someone take another look at your exhaust system. My plane was purchased with a relatively recent new exhaust system installed. I noticed that I was feeling unusually fatigued after flying but the little dot on the sticky CO detector looked OK (obviously not a precise instrument!). I happened to purchase a second headset for my wife to use (Lightspeed Delta Zulu) which has a built-in CO detector. It was fine on the ground, but in a climb it started squawking at me about increased CO. Seemed to resolve again in level flight, but it was definitely heading in the direction of triple digits during climbs and slow-flight practice. Turns out that whatever yahoo installed the exhaust system decided to use some non-appropriate sealant. My mechanic figured this out during the first annual and was nearly throwing things in frustration.
The values you're showing are suboptimal but not concerning for incapacitation. Doesn't mean the problem can't get suddenly worse though, so probably worth your while to at least have someone take a close look at the usual suspects.
plane is a Cessna 182H with O470. Couple of years ago after being a bit more fatigued after a flight I purchased a sensorcon CO detector. Was seeing 30 by me and higher in back. Thought it was a bad seal. They sealed doors and was about the same. Went in for annual and found cracks in the exhaust manifold. So it was replaced. And the numbers went down. Zero to Low singles less then 5. I fly with it Everytime. Well I noticed the other day the numbers seemed to climb. Need to experiment more. Vents open in front readings 8-10. But in back readings jumped 15-28. Now I think my sensorcon might be past date. So I’m ordering a new one. But anything I can test to troubleshoot. I think on ground idle was zero oe very low and on climbout was low as well. Levels seem to go up with level flight.
