Dryer quit drying so I took it apart and tested the thermal high limit, operating thermostat, and fuse. All tested OK on my meter. Put everything together and watched it run with the case open. The gas would flame OK for one cycle and then would short cycle or not come back on.

Got some advice that it was the coils so I replaced them. Put everything back together and watched it again. Similar thing happened. First cycle comes on and seems to run OK for about 1 minute. Then the second cycle will shut off very quickly after the flame comes on, maybe 10 seconds or less.

I've cleaned everything out when it was apart and airflow is good.

Is it possible that something is failing after it gets heated up? What could it be? The high limit switch, flame sensor?