On STAGE 2 tunes, do secondary O2 sensors get used at all?

[GtiGyver]

On STAGE 2 tunes, do secondary O2 sensors get used by the ECU for fuel trim or ignition timing?
Or can they be removed completely (disconnected)?
If not, can they be removed from the exhaust, but still electrically connected? (tape and stow)

Thanks

[Scharbag]

Pretty sure they are only there to measure catalytic efficiency. So, likely tape and stow would be fine. Unplugging them will likely throw codes.

[GtiGyver]

Originally Posted by Scharbag

Pretty sure they are only there to measure catalytic efficiency. So, likely tape and stow would be fine. Unplugging them will likely throw codes.

That's what I'm thinking too. But before I commit to that solution, I was hoping to hear from someone who tried.

[KawBoy]

I physically removed mine and "ECU deleted", so no error codes or anything.

[bmwfst1]

how do you pass inspection or emissions test?

[KawBoy]

Florida doesn't have emission test.

[GtiGyver]

Originally Posted by KawBoy

I physically removed mine and "ECU deleted", so no error codes or anything.

What tune do you have?
I never heard of ECU deleted. What ECU does it refer to?

[KawBoy]

Originally Posted by GtiGyver

What tune do you have?
I never heard of ECU deleted. What ECU does it refer to?

ECU deleted O2 sensors. Secondary sensors deleted on the DME.
Randy's Epic tune.

[--Aramis--]

Interesting, i'll plan on remove them after stage 2 tune

do you think all stage 2 "delete" them or just delete/move their monitoring and for deleting them physically it's another process/modification?

It's good to know that EPIC motorsport could do that, you have done that tune at Epic workshop directly or it could be done remotely?

[KawBoy]

I believe all tunes can provide the O2 delete option. I specifically asked Randy for the feature as I didnt want to have the O2s hanging. First tune he sent didn't have it enabled, so I emailed him, and, in a few minutes, he sent me a new file with the delete.
The whole thing was done remotely. He has sent me several corrections since then, trying to fine tune my motor.

[GtiGyver]

I still wonder though if the secondary O2 sensors play any role in the short/long term fuel trim and ignition timing.

[pbonsalb]

Some say there is a feedback loop. I believe this is true at least on reasonably modern engines. For that reason, using 02 modifiers can cause issues over time. Deleting them or simulating them in the tune does not cause issues.

[Soden82]

I was always under the impression they cause LTFT to be altered and reduce performance over time. Maybe it’s not the same for the S65 compared to other FI cars

[pbonsalb]

Right, but I think if the simulation is done in the tune, there is no issue. It is when you try to trick the sensor and get it so a CEL is not triggered but the signal is not exactly what is expected, like with a mini cat or 02 modifier, that there could be issues.