AFR on Dyno Vs Street or Trac

Does anyone had the problem that you tune a car on the dyno doing a straight AFR line and as soon you put the car on the street the mixture get lean?

I've seen this happen when the Dyno Cell doesn't have good ventilation -- you have a giant exhaust gas recirculation -- you end up removing fuel during the dyno session, then when given air with more oxygen, you are too lean.

You need to monitor the temperatures for sure, but also the dyno may not be loading your engine in a realistic way, especially if it is a simple inertia dyno. It's normal to need adjustments when you get on the road.