RomRaider

I have a Subaru Legacy GX 2,5 N/A.

After buying several cables I finally bought a cable that works fine with SSM.

I am relatively new to tuning and understand the basics.

I am a bit hesitant to try any flashing at this time due to a number of reasons, cost if I brick the ECU ,my air-intake is non-standard .
Together with this the age and fuel in my country leads me to believe I need to understand more about the ECU workings.

Currently the l/100km is averaging around 8 + - 0,3 driving very conservatively with little or no aircon (only on downhills).
Although I am running hho , I used to get the occasional Knock code (before hho) if checked periodically on my CPR123 Launch reader.
Installed additional WBO2 guage , with this can I run slightly leaner via ecu mapping and what would be a good value for this EJ251 engine .
What I find I can lean the vehicle out manuall BUT when the vehicle is in idle it reverts very close to the AFR of 14:7.

When I manually lean it out slightly(15-17:1) the accelerator off idle is wicked , but then on long downhills when I do not use any accelerator, the Engine light comes on permanently- after about 5 km on low load the Engine light goes off.Only knock sensor in history DTC's.

My model appears to be like an unknown entity with little technical information regarding any mapping or economy /power tuning .

Any advise would be appreciated.

regards
Bradley