O2 sensor and LTFT weirdness ?????? Help !

[The Alchemist]

Hi guys,
I got a real doozy in the workshop this week
a 2004 LS1 Corvette electronic throttle body, procharged intercooled , long tube headers etc doing some weird shit I've never seen before!
See attached log.
Basically the RHS O2 sensor had rubbed through on all 4 wires on a heat shield under the car.

I've replaced both sensors with new, it has new coils, leads and plugs as well.
As you drive along the first thing you notice is both O2 sensors read exactly the same in perfect sync. I've checked this on another scan tool and its the same. All LS1's I've ever tuned had slightly out of sync O2 voltages with varying voltages as well.
The 2nd thing that happens is that as you warm the vehicle up about 7 minutes into a light drive the LTFT on one bank jumps to 20% instantly with NO change in the O2 sensor on either bank ( cos they stay the same always ) or in the STFT's. Then it suddenly drops back down to "normal" again.
3rdly the O2 sensors seems to sometimes only drop to 450mv not 20mv like it should as it oscillates.
I think the ECU is toast personally.
Do any of you have other ideas? cheers,
Mike

[joecar]

Are there any short-circuits in the HO2 signal wiring elsewhere in the harness...?

[joecar]

Does bank2 exhaust header have an airleak...?

[The Alchemist]

I did a relative compression test today and found it to be very up and down . I pulled the newly fitted plugs ( by the customer ) and found bad oil deposits on one section of the porcelein on every plug, like really black which would have been causing arcing and misfire. Also cylinder misfire detection on cylinder 1 was counting up . Given the tune had way to much timing in it I'm suspecting a hurt engine and have finished up the job subject to the customer coming up with the $$ to fix it properly.

[joecar]

Mike, do you any have pic's of the plugs...