Problem code p0642 car runs fine in heated garage once out in freezing temps starts to overfuel untill it floods out completely will not restart untill taken back into heated garage when rescanned p0642 remains and all 4 o2 sensors are stuck on rich
This is a code for voltage reference for sensors and it could be any of them which is a lot of testings.
I would suggest starting with the Engine Coolant Temperature sensor since it is temperature related. It could be a loose or contaminated wire socket and does not necessarily mean a bad sensor.
Check the connector for looseness and contaminations.
If you have a scan tool to monitor the voltages, that would be the easiest way to go about.