Open loop with STFT. Say what?

[dekes1]

Sorry for a dumb question, but during WOT the ECM goes open loop which means the O2 sensor is ignored. But yet I'm still seeing STFT adjustments during the WOT pull. How can the ECM know about rich/lean conditions and make adjustments if the O2 is ignored?

Additionally, during WOT, PE is basically my source of fuel parameters but if I'm seeing STFT adjustments, what table would define the amounts (the limits of) what the ECM can apply for STFT?

E80, LTG

[KLUG'S SS]

Hmm that's an interesting question. As many know on older LS operating systems in particular their was always the tab where you could enable/disable use stft during open loop. On anything newer heck even back to the E38 pcm that tab hasn't been implemented in any newer platforms. Ltft disabled you've seriously got stfts adding in power enrichment? I've been tuning for awhile and don't recall seeing this off the top of my head. On newer operating systems I mean.

[cobaltssoverbooster]

some newer ecu's with wideband option factory are going this route to prevent piston failure in wot

[KLUG'S SS]

Good to know