2ZR Turbo Yaris

[tmontague]

Excellent to hear, I hope it stays this way.

FWIW I monitored O2 sensor temp last year using my ultra gauge, I don't remember if it was s1 or s2 but it read between 1000F and 1400F+ if I really got on it.

Be careful about using a spark plug defoulders with the p0420. I tried that on my 3.6R subie and I ended up eventually triggering 2 or 3 other O2 codes due to voltage and slow response time - although the original p0420 never came back during the defoulder install. I also confirmed via fuel trims that is was messing with the fueling a bit.

I remember you mentioning the secondary O2 sensors in newer cars actually having an effect on fueling and looks like you were bang on. You can use O2 sensor voltage to diagnose if it is in fact a bad catylitic converter or not via watching its waveform or just careful monitoring of its voltage while on quiet back roads.

How exactly does the resistor work? I'm curious based on how it is wired in, what does it actually do to the wires.