Please school me on the operation of a 02 sensor

[billschroeder5842]

I got some weird codes (13) on my 02 sensor so please school me in the operation of our three-wire O2 sensors system. I get that the two wire give signals to the CCM to help decide open/closed loop and the third wire is for the "heat element."

Does the heat element heat up on key forward or engine started and running? Does the heat element go off after a point? Is that triggered by temperature or by timing? What would cause a SES light to come on briefly, throw a code, then go out? Does the addition of headers (I just added them a few weeks ago) cause a reading difference even after a top notch tune?

I not super worried (I'll just swap in a new 02) I'm just curious how the system works and what triggers what.

[SBAquaLT5]

Are you running long tubes? The O2 sensor is designed to work best in a specific temperature range. If the sensor is moved further away from hot exhaust gases, the sensor is not always as effective. Especially when old. This is one reason why emissions states don't like long tube headers.



The sensor operates in a constant sinusoidal voltage swing. Once the engine is running in closed loop, monitoring the O2's, it's constantly going rich/lean and measuring the voltage swing on the O2 to tune itself. When sensors get old, or when cold they don't respond as fast. The heater is designed to give the sensor a boost to be more efficient. Exhaust gas is going to heat them hotter than the heater ever will on its own. But they need a boost to get their quickly.

[XfireZ51]

Originally Posted by billschroeder5842

I got some weird codes (13) on my 02 sensor so please school me in the operation of our three-wire O2 sensors system. I get that the two wire give signals to the CCM to help decide open/closed loop and the third wire is for the "heat element."

Does the heat element heat up on key forward or engine started and running? Does the heat element go off after a point? Is that triggered by temperature or by timing? What would cause a SES light to come on briefly, throw a code, then go out? Does the addition of headers (I just added them a few weeks ago) cause a reading difference even after a top notch tune?

I not super worried (I'll just swap in a new 02) I'm just curious how the system works and what triggers what.

Bill,

The heating element gets the O2 sensor up to operating temps quicker by not relying on only exhaust temps to heat it up. When does the MALF code show up?
Immediately after start up, at a certain coolant temp? Need a bit more info on the circumstances.

[billschroeder5842]

Thanks everyone for your replies.

This has only happened once and the SES light was only on for about 10-15 seconds. I have a set of long tube headers on the car and the car was "luke warm" at the time. I took the car for a ride and there was nothing wrong. I cleared the code

I have since had about 8 on/off sequences since I had the light-- OPS normal.

Maybe it was just a "thing" but it got my curiosity going as it has never happened before.

[XfireZ51]

My SWAG is that its going lean momentarily, probably when it goes into Acceleration Enrichment.

[Ccmano]

Bill,

When you added the headers did you have the tune updated?
H

[billschroeder5842]

Originally Posted by Ccmano

Bill,

When you added the headers did you have the tune updated?
H

100% yes. Steve Schroder from Crossed Flag in Magnolia, TX did the headers/exhaust, injectors, coils,....etc. Steve has a Mustang Dyno at the shop and did a great job and really dialed in the car,

BTW.. I have had ZERO lights since that one "moment". I'm chalking it up to a momentary computer "brain fart" as the cars runs extremely well.