Well replaced the front 02 sensor, it was about 90% jet carbon black. Also changed the pcv valve and inspected the rubber hoses, all seemed fine. Here is another strip chart, front sensor voltage is indeed a bit higher, scale is 0 to 1 volt.
Is the Focus SVT converter really 2 parts? It looks like Header, o2 sensor, oval cat segment, rear o2 sensor, then another bendy oval cat section before it bends up and around the axle.
I have seen the P0420 come and go once since