KTuner.com

I've noticed that ECT2 temp is stuck at 35 degrees leading to both oxygen sensor and catalyst monitors not running, with my scan tool I viewed ECT2 sensor voltages which changes from 3.6volts at cold start down to 1.7 volts at normal operating temps but the parameter for ECT2 temp never changes from 35 degrees, I replaced ECT2 sensor at the bottom of the radiator and retested and nothing has changed.

If the voltage is changing then it sounds like you have it disabled. I'm assuming you've tried returning to factory.

I don't have it disabled, interestingly I noticed that ECT2 changes normally when logged by ktuner but it stays at 35 degrees when monitored by my scan tool!

I will check with a different scan tool later today, I'll also re-flash the ecu and see what happens..

If it changes in KTuner then it is functioning properly. That's good news.