Periodic CO warnings on G3 SR20

Have a G3 SR20 and we are randomly getting CO alerts which tend to be on climb out and are elevated levels for a minute or two, but not crazy high/emergency level. One of our pilots has a lightspeed headset which provides a graph and it tends to peak at like 30-50 ppm for a minute or so during taxi

at cruise we have had a transitory alert once but it went away with the vent open, and seems to be at 0ppm generally. on descent you can see it start to spike to around ~5ppm then will jump again when taxiing to 20+

obviously this is difficult to troubleshoot, and doesn’t appear to be related to the heat exchanger. is this common? could a poorly sealed (but closed) door cause this?

With a SR20 G1 I have had an alert on the ground with the door open during runup once or twice, but it is a very rare event. I have never had the alarm go off in flight and my CO reading is nil or below 5ppm.
Hope this helps

So there is an exhaust inspection AD on the G2 SR20, not sure if it’s on the G3. I would say 30-50ppm is unacceptable unless you’re taxiing behind another airplane.

In cruise if you’re LOP you won’t get CO.

I suspect you have a leak in the door seal given it drops in climb. The fast air movement relative to taxi likely means most CO doesn’t get in the cabin.

You may need the door seals done.

That said, I’d dew have the exhaust looked at closely as CO isn’t something to mess with.


I had intermittent CO readings, usually around 9-ppm during the first year. At the next annual, they did a cleaning/polishing of the flex joint. The problem went away. Did manage to get a CO reading when doing prolonged slow flight a couple of months ago.