Find the EFILive custom operating system that matches your vehicle's current operating system here:
http://www.efilive.com/downloads/dow..._customos.html
Save your existing tune.
Use the full flash features to reflash your PCM with the custom OS.
Please read the warnings prior to the full flash.
Reflash the calibration from your saved tune into the PCM.
Rescale the MAP sensor {C6301} (Engine diagnostics->MAP->Parameters->MAP Sensor Scaler) so that at key-on the MAP reads 50kPa in the Scan Tool.
Adjust the EFILive Custom Calibrations as follows:
Code:
LABELS Selection
Parameters Value
{A0000} Forced Octane Scaler Disable
{A0001} Forced Octane Scaler Percentage 100 %
{A0002} Octane Scaler Limiter 100 %
When tuning your high and low octane spark maps, you can set {A0000} to Enable, and then set {A0001} to 0% to force the PCM to use the low octane table exclusively, and then set {A0001} to 100% to force the PCM to use the high octane spark map exclusively.
The {A0002} value is a limiter that limits the maximum adaptive spark value, regardless of the settings in {A0000} and {A0001}. You would set {A0002} to some value less than 100% if you knew you were going someplace that had only had low grade fuel available. It keeps your spark advance from climbing all the way into the high octane table while still allowing the spark to "adapt" for knock.
Recalibrate your VE table to suit the new (2-bar) MAP values.
Regards
Paul