The EVOX does not have a wideband O2 sensor, so it is unable to accurately display AFR. It would appear that you are now seeing proper AFRs and perhaps there was some sort of mechanical issue associated with your lean condition. It could also very well mean that the wideband used to measure your AFR was faulty if you are now seeing richer readings.

Our maps, while designed to increase performance are also designed to be safe and conservative. If you are seeing overly lean conditions and lots of aggressive timing, please report these findings as this is not our tuning strategy.

Travis
COBB Tuning

 

We are aware that the stock Evo X does not have a wideband sensor. However when clients come in to dyno their car with wideband, and we place the wideband sensor upstream in the exhaust tract and NOT with a tailpipe sniffer, you can rest assured that our readings are accurate.

We use the same wideband on our dyno that Pratt & Whitney use to test rocket engines with for the military.

 

Thanks Travis, everything seems to be working well now. I will notify the shop that did the dyno runs to let them know the difference in A/F ratios between my AEM wideband meter and their instrument.