Hab ich eben grad gefunden. Könnte evtl. hilfreich sein.
Most modern vehicles use an Oxygen (O2) Sensor to feed back the Air/Fuel ratio the engine combustion cycle is running at. The Air/Fuel Ratio (AFR) is represented by a voltage from the O2 sensor. The OEM ECU can modify the amount of fuel injected based on the voltage from this O2 sensor to achieve a pre-programmed target AFR. This is called closed-loop mode. Closed-loop mode is usually used when the vehicle has been driven at light throttle settings, or 'cruise'. In closed-loop mode, the OEM ECU also varies the AFR very slightly so the O2 sensor voltage oscillates in time with the AFR variations. This is a form of diagnostic mode used by the OEM ECU to ensure the O2 sensor is operating correctly. This is another reason why you cannot substitute a constant voltage for the O2 sensor to 'fool' the OEM ECU. When the engine is under heavy load, e.g. heavy acceleration, the O2 sensor is disregarded as older O2 sensors did not have the AFR range to provide an accurate AFR when the engine is run richer for power. This is called open-loop mode. The latest vehicles have higher quality O2 sensors that have extended AFR ranges and therefore the amount of time closed-loop mode is used. When ANY piggy-back ECU is installed and you adjust the AFR's, the OEM ECU will always try and recalibrate itself to the pre-programmed AFR's in closed loop mode. This can undo the tuning work you have put into your installation. The MAP-ECU2 O2 Adjust feature allows you to 'fool' the OEM ECU into thinking it is still running the pre-programmed AFR's even though you have modified them. We provide a 26 x 19 (494 zone) table, which is the same resolution as the fuel table, so you can adjust the O2 sensor voltage by up to +/- 1.00 Volt in 0.01 Volt increments. As we modify the voltage from the O2 sensor, the OEM ECU will still 'see' the voltage oscillate as it varies the AFR slightly. www.performancemotorresearch.co.nz/forum/index.php