Simulated narrow band output - experiences?

[Jonas_R]

I'm looking to use the simulated narrow band option in zeitronix to lean out the cruise a bit.

As far as i understand the zeitronix unit will trick the ecu.

But when will the ecu stop using the narrow band signal? Because the zeitronix unit does not have a max rpm setting or any other setting. I don't want it running to lean.

Anybody that has used this option before?

[ranz]

ECU stops reading the lambda @WOT and does not read it @ could conditions (the time should be different, depending how could the engine is).

[jade]

I'm looking to use the simulated narrow band option in zeitronix to lean out the cruise a bit.

As far as i understand the zeitronix unit will trick the ecu.

But when will the ecu stop using the narrow band signal? Because the zeitronix unit does not have a max rpm setting or any other setting. I don't want it running to lean.

Anybody that has used this option before?

Its only works at low RPM when the narrowband is working

Never had much success with it myself

[prj]

Narrowband is used only on light throttle conditions.
But your fuel trims will be off if you do it this way and it might drive rough during warmup.

I solved it like this...
1) I left my simulated narrowband at 14.7, as it was.
2) I turned off closed-loop feedback on everything BUT idle and revving without load in the ECU.
3) I re-tuned the car to run on 15.6-16.0 AFR on light cruise.

This way, when your car is tested for emissions, you will still pass emissions, because they rev it at idle (and narrowband keeps your mixture correct at 14.7, even if something is broken), and at cruise you have better fuel economy (at the cost of emissions).
Because you have a wideband gauge, you can see if your mixture is off.
Plus, the fuel trims will be okay, so you won't get fluctuations and bad running on startup.

As I see it, the narrowband is mostly there to protect the cats + for emissions. If your mixture goes rich at cruise, you can melt your cats. However, if you have boost leaks, then you will have lean mixture at cruise, not rich. It's actually very unlikely for you to run rich on cruise, and you have your wideband gauge to verify it.

If you can send me the file from the fuel chip, I can probably modify it for you. It generally runs the same on most cars with standard setups.
I personally would not recommend tricking the ECU with the wrong signal.