Originally Posted by mcp202
Makes sense. I was wondering about the O2 readiness light when you show up to the dealership with an Akra Evo and the light is off....
It is not about the light on the dash. ESS's tune doesn't show the O2 sensors being ready(when being checked for smog) vs Evolve which does. ESS I believe utilizes a different approach. Either way, you want to flash back to stock before going to a dealer.