Closed loop activation - STFT
Hi everyone.
Trying to understand the way ECU switches between CL and OL.
From the experiance working on many cars as LPG installer, as soon as O2 sensor starts responding (0-1V or 0-5V) ECU starts doing its calculations as STFT.
I fitted MTXL and send narrow simulated signal to the ECU and what i noticed is when i start the car up MTXL gauge displays "heat", as soon as its ready AFR gets displayed as well as narrow signal is beeing send to the ECU but ECU stays in OL with STFT 0%. If i leave it idling like that it will stay in OL with quite lean mixture AFR over 15. As soon as i rev it ECU switches to CL and AFR gets back to normal target 14.7. Is that normal behaviour?
Other question, what is the AFR target when engine is cold, is it different to warm target 14.7?
Other thing what fuel trims do you have at the idle LTFT-fuel trim in use and STFT-oxygen feedback and another thing, can decat pipe afect AFR and fuel trims at idle and mid range load as it is just behind O2 sensor?
