My glanza started touching fuel cut with just an air filter and bypass restriction. Boost pressure isnt the issue. Aslong as it doesnt go past 0.8 bar its fine. Downside is the boost creep which needs to be resolved. I'm running a full cat back system, decat, air filter, at 0.3 bar and it still gets the light to come on. But each car is different, some react differently to others. Its alright doing breathing mods but the manifold and small wastegate are the cause of most problems. If you dont mind getting your hands dirty, do the manifold and turbo. Pretty sure there is guides on how to do so. D