Is the air to fuel ratio from the Tech 2 a reliable tuning source, or do you have to get an aftermarket wideband O2 sensor and meter for tuning?

 

If it is like my autoxray scanner it is not a good tuning source. It is just a readout of what the pcm is commanding not the actual A/F Ratio. For example in closed loop it always reads 14.7. In open loop it reads whatever Open loop AFR table tells it to.

 

Does anyone know if the A/F ratio on the Tech2 is the same as on Autoxray?

 

I don't think the tech 2 has any means of collecting AF ratio ie a WB O2 sensor.