New sensor arrived in only 2 days, but didn't seem to help.
Replaced the sensor, set to 350. In 20 minutes the oven only got to 325. Set it up to 450, 4 minutes later it had only reached 350, then 12 minutes after that, it finally got to 450. I tried setting it back down to 350 and in 15 minutes it was at 385, 15 minutes after that it was at 330. These temps are all checked by an oven thermometer, which I have no way of verifying, so it's hardly scientific.
I was really hoping the new sensor was the answer, but the original problem seems to remain. Any more ideas?
Thanks for your help.