Disabling the rear O2

[ButtonPuncher]

Under Scalars->rear_O2_sensors

Do I need to set heater_bank_1_downstream and hego_configuration both to zero?

Right now I'm getting a P0420 CEL. It also runs INSANELY rich at startup on the "Premium" tune that Brenspeed sent me.

I want to disable EGR and the lower O2 on the "Stock" tune and give that a shot.

Thanks,
BP

[warmonger]

Well there is a swtich to turn off the rear O2s, then there is a separate switch to turn off the rear O2 heaters also.
Also in a separate section of the scalars is the EGR type switch. Setting it to 2 or 3 shuts it completely off.
If you don't shut all of them off you can still get CELs

[ButtonPuncher]

Also in a separate section of the scalars is the EGR type switch. Setting it to 2 or 3 shuts it completely off.
If you don't shut all of them off you can still get CELs

2 or 3? I wonder of setting the EGR to 0 is causing the CEL. Why wouldn't 0 be off and 1 be on? More SCT weirdness.

Why would anyone want to keep the heater on but disable the sensor? I guess you could cut the wires to the PCM and run them to an AFR gauge but its after the CAT so that's useless. Again, more SCT weirdness.

Thanks,
Ben

[warmonger]

2 or 3? I wonder of setting the EGR to 0 is causing the CEL. Why wouldn't 0 be off and 1 be on? More SCT weirdness.

Why would anyone want to keep the heater on but disable the sensor? I guess you could cut the wires to the PCM and run them to an AFR gauge but its after the CAT so that's useless. Again, more SCT weirdness.

Thanks,
Ben

Because the numbers indicate types of egr systems, not On/Off. This way the switch type (pretty sure its 3) just tells it the system doesn't exist.

The reason you have a separate switch for the heaters on the rear O2 sensor is so you can disable the sensor even though they may be left in the car. A non heated O2 sensor will be ruined if left in the exhaust. So you can disable the sensor while it is in the car...maybe for diagnostics or something and not ruin it.

But in most cases people pull them out. I just shut all the switches off for the rear O2s if someone wants them off.

[posthuman63t]

Also in a separate section of the scalars is the EGR type switch. Setting it to 2 or 3 shuts it completely off.
If you don't shut all of them off you can still get CELs

Elaborate a little? I went through all the scalars and found nothing that mentioned EGR switches. I have all the heaters and switch in the rear o2 scalars turned to 0, so I believe I am still tripping a CEL because of this EGR switch.

[99cougar]

Elaborate a little? I went through all the scalars and found nothing that mentioned EGR switches. I have all the heaters and switch in the rear o2 scalars turned to 0, so I believe I am still tripping a CEL because of this EGR switch.

Go to Scalars>System Switches>EGR_Type_Switch then select 2 to turn it off.

[posthuman63t]

wow, I can't believe I didn't see that...Thanks 99cougar

[99cougar]

wow, I can't believe I didn't see that...Thanks 99cougar

lol no problem.

[ButtonPuncher]

OK, I just flipped through my SCT manual and it also says 2 to disable EGR.

Is it something Contour specific that requires it to be set to 3? Or is just that anything 2 or over shuts it off?


BTW, that makes sense about the number being the EGR type. With it set to zero, I can still feel a little bit of surging like it's trying to activate the EGR. Not the major surging like having it set to 1 though.

Thanks,
Ben

[Kremithefrog]

What is the advantage of turning the egr off?