If the signal and ground are reversed, the lambda value might read high - say 20, and the car may run badly due the ECU being fed an incorrect negative sensor voltage. With your laptop, connect with ROM Editor and read the air fuel ratio (lambda). Start the car and read the airfuel ratio from the wideband's display. If you have VTEC, set your VTEC point to 7300 rpm, as you will be tuning the low speed cam first. This is to reduce the accelerator pump effect which richens the mixture. Set acceleration enrichment to zero - which due to a bug in ROM Editor 2.5 is labeled as cranking enrichment. Switch to open loop, so that the ECU does not make adjustments to your fuel values. Your engine may require more or less fuel for maximum power. Remember that these target values are just suggestions. This will get you closer to peak power for 750 mb air pressure. These values should be found in your wideband's documentation.Įdit Target Lambda and change the 750 Mb column to 12.94 by pressing the J key. Open settings, click edit conversion table under Lambda and type in the voltage-airfuel values for the wideband you will be using. The other two wires, typically green and white are ground and signal, which are connected to the wideband's ground and signal output. Even if you do get this error the ECU functions normally.
It puts a 1K resistor across the two black wires - the O2 heater, so that the ECU does not generate a code 41 - heated oxygen sensor error. You can make an adapter (using the plug off a dead O2 sensor) that connects the 0-5V wideband output to the stock oxygen sensor plug. 3 0-5V Output from wideband to stock O2 wiring.1 Power and ground cables for the FJO wideband.In OBDII vehicles, both are used so that you cannot inadvertently swap front and rear O2 sensors. Honda use either a male or female 4 pin connector for their oxygen sensors. Remove the stock oxygen sensor and install the wideband O2 sensor. Installationįor instructions to install the PLX wideband, see this application note: Note - you must have Stage 4 as datalogging is used. The stock O2 sensor is very inaccurate for anything other than 14.7:1 air fuel ratio. That output is fed back into the O2 sensor wiring where ROM Editor or HondaLogger convert it back into a precise air fuel ratio. Most wideband meters - (the ones that are of any use in tuning here) have a 0-5 volt output proportional to air fuel ratio.
Hondata has had extensive tuning time with two wideband lambda meters, the PLX and the FJO. This does not replace dyno tuning, but augments it. Using a wideband in on road conditions will enable more accurate fuel tuning. Another good reason to tune part throttle correctly.
If you are running closed loop and your part throttle fuelling is incorrect, your full throttle fuelling will be affected. Typically you car will run leaner off the dyno than on by about 3/10ths of a point. Dynos do not accurately represent real world conditions like under-hood airflow at speed and RAM air effects. (poor fuel economy, roughness, stumbling) Very few dynos are capable holding a constant load for part throttle tuning. Part throttle where you spend most of your driving time and is the most common area for complaints. Why use a wideband? Full throttle tuning only tunes 1/5th to 1/6th of the available map area. The article is written for the staged system (pre S300). Technical Information Wideband Tuning Note