I failed smog. Heated O2 wiring questions now.

[dyeager535]

O2 sensor generates a voltage based on the O2 present in the exhaust stream. But they have to get up to temp before they become "active". This is why some problems occur when swapping to headers on trucks like ours.

Theoretically you are right, high temp=lean, low temp=rich, but there are a ton of factors to consider...decel, idle, startup, engine temp, and so on.

I am far from an expert, but GM did things like "closed loop timers" (how long it takes to go closed loop after start), looks at engine coolant temp, plus watching O2 sensor voltage to determine if it's "ready" for closed loop.

That's one advantage to tuning, if you go with a heated O2 sensor, you can "force" it into closed loop far faster if the engine will allow it.

 

[British Slave]

O2 sensor generates a voltage based on the O2 present in the exhaust stream. But they have to get up to temp before they become "active". This is why some problems occur when swapping to headers on trucks like ours.

Theoretically you are right, high temp=lean, low temp=rich, but there are a ton of factors to consider...decel, idle, startup, engine temp, and so on.

I am far from an expert, but GM did things like "closed loop timers" (how long it takes to go closed loop after start), looks at engine coolant temp, plus watching O2 sensor voltage to determine if it's "ready" for closed loop.

That's one advantage to tuning, if you go with a heated O2 sensor, you can "force" it into closed loop far faster if the engine will allow it.

That little word "IF", is that a typo or is it what you meant? "than" maybe?????

 

[imiceman44]

That little word "IF", is that a typo or is it what you meant? "than" maybe?????

It is IF.
Because it's if the temp is good enough and everything else is the way the ECM wants to see it, the only difference is the O2 sensor will give the answers faster than the non heated one.

 

[British Slave]

I'm learning. And that's why I asked.

 

[jekquistk5]

Thank you for this. Now i know why my truck runs like crap lately. It runs really rich and I have to keep my foot on the gas till it heats up then in leans out. So I guess I need to throw it on a switch or a constant 12V source instead of the keyed ignition power.

 

[British Slave]

Just how hot will the heated O2 sensor get without the engine running?