Problem with Fatory Tune

[PeterT]

Hi
After loading a factory tune to my 2004 Monaro LS1 (read GTO in USA) with the only changes being the final drive ratio and tire diameter changed using the wizard in Editor I am getting the following.
Firstly wihile loading the tune I get the MIL flash ! wihich made me suspicious.
The car runs without any noticable difference however at around 1200 to 1500 RPM and full throttle (100% open). the MIL comes on with The Codes are P0151 O2 sensor circuit low voltage Bank 2 sensor 1 and P0131 O2 sensor circuit low voltage Bank 1 sensor 1

This is very repeatable and confusing that it happens on the factory tune.
I have had the vehicle since new and never had this issue.
this has only happened since loading final drive ratio and tire changes.

Any help would be greatly appreciated

[kevin87turbot]

I doubt that those codes are being caused by the calibration. But here's a quick way to test it...just load the original cal file back in there. That'll be a quick test. If it still does it, you can dig further. It's possible that the O2 sensors are just old and need replacing.