I am dealing with exhaust CPS error as well.
Same thing as you had, VCG leak poured into the sensor and connector.
I ordered the sensor, o-ring and the bolt from fcpeuro.
Went to replace it, but for the life of mine couldnt take the stupid bolt out. Frustrated I just cleaned at connectors and the sensor harness with MAF cleaner.
The light has been off for me for almost a week, hopefully it will stay off. Else I do have the sensor, o-ring and the screw handy. But that 5mm hex is driving me crazy. I already dropped one 5mm allen key into the underbelly, I have one more but it just doesnt budge. **** scared to strip that bolt as well.