O2 Sensor Fix

[dla]

the downstream O2 sensors doesn't do anything to your ECU, it's the upstream that tells it to lean or rich the condition. they just merely tell you that you're polluting the environment since the cat is not doing its job.

Wrong. The downstream O2 sensor also gives feedback to the ECU used to adjust air/fuel trims to make the catalytic converter run efficiently.

 

[lincolnshibuya]

damn I'm so stupid, I don't know about that... :notworthy

this is taken from 2002 ford explorer v8 FSM:

The front HO2S:

- creates a voltage signal dependent on exhaust oxygen content.
- provides feedback information to the PCM used to calculate fuel delivery.

The rear HO2S:

- monitors oxygen content after it flows through the catalytic converter.
- provides a voltage to the PCM used to calculate catalytic converter integrity.

 

[dla]

damn I'm so stupid, I don't know about that... :notworthy

this is taken from 2002 ford explorer v8 FSM:

The front HO2S:

- creates a voltage signal dependent on exhaust oxygen content.
- provides feedback information to the PCM used to calculate fuel delivery.

The rear HO2S:

- monitors oxygen content after it flows through the catalytic converter.
- provides a voltage to the PCM used to calculate catalytic converter integrity.

So you are saying that the Ford ECU plays no active role in maximizing converter efficiency?

 

[lincolnshibuya]

So you are saying that the Ford ECU plays no active role in maximizing converter efficiency?

clearly an emission thing.
if you could provide technical references that say otherwise specific to 02-05 Ford Explorers. remember we're talking about fuel/air trims here not converter efficiency (as what you mentioned)

note that even you get a p0420/p0430 for a bad cat, you can still drive the car without any issues..