Solution seems to be divide by 14.7.

It's hard to redo logs from 2 years ago on a dyno before the engine was rebuilt. I just wanted to know how rich it was running back then. It's still got a rich running problem.

Hi Ugnius,

That did not work. Settings were Lambda and I changed to AFR Gas and it made no difference to how the old logs displayed.

All my logs before the 1 Dec 2016 show the very high numbers. All my logs after that show AFR around 14 like they should.

Hi,

I have recently opened some of my old logs and my AFR numbers don't make sense.

For instance they are scaling between 153 and 430 in one old log.

My new logs are fine.

Is this a known issue and is there a scaling factor I can use in my spreadsheets to correct this to actual AFR?