06 Ranger O2 Sensor wiring problems.

[Mark Templeton]

I have an 06 4.0 L Ranger in which the passenger side rear O2 Sensor got to close to the exhaust and the connector melted. Someone before I owned the vehicle cut the connector out and spliced the wires with crimp-on connectors. Lately I have been getting O2 sensor codes out of the code reader and decided to replace all the O2 sensors. When I pulled the passenger side back sensor it doesn't have a snap-on connector. The 4 wires going to this sensor from the truck wiring harness are colored as follows: White w/ Black Stripes, Blue w/ Pink Stripes, Red w/ Green Stripes and Grey with Red stripes. I have bought the right harness side connector half, I just need someone to tell which of these connect to the new Bosh O2 Sensor with two white wires, one black and one grey wire. Thanks for any help/advice you can provide.
Sincerely, Mark Templeton