DH3069

I took my truck to get a safety and emissions test to register in Utah. The state uses the I/M monitors on the truck to check emissions. My truck failed for O2 sensor, Heated O2 Sensor, and Catalyst. I tuned my ECU back to stock and the O2 monitors are now ready and a short drive in the morning will clear the catalyst monitor.
Does custom tuning affect (disable) the O2 sensors? I've got the Torque app and BT connector and the O2 sensors don't show any reading when it's tuned but gives voltage readings when it's stock.

TheWhiteBeast

Your o2 should show voltage at all times. It's how the motor "knows where its at".

RES4CUE

I forgot to put mine back to stock before my emmisions and it failed also, backed it out of the bay and returned back to stock, let it run for a bit and pulled it back in and it passed no problems.

I am not sure but the o2 sensors may be disabled through the custom tune to get more A/F ratio.