Hay Gene ,
I did what you said with the oven thermometer in the oven set at 350 degrees for 15 min. Temperature was 250 on thermometer

. 100 degrees to low. This is an electric whirlpool GR448LXPB0 ser# RR4115706. Like I mention before I already replaced the lower element. I'm leaning towards the oven temp sensor??
Your help is greatly appreciated.
Dave