Hi, I have a 2014 Demio 1.3L and at random intervals and without a pattern it misses. It only happens when I'm in traffic lights or in traffic (idling) and the engine is warm. Something it drops the idle but never below 500RPM. And also the Km/L isn't showing as usual and the numbers aren't linear anymore, for example it's at 25Km/L and I give it some gass it drops down to 4Km/L These are the things that I've already replaced/switched out

• The spark plugs

• Tried a set on second hand coil on plugs

• Calibrated the gass paddle to the throttle body

• •Tried a different second hand throttle body and MAP sensor • Cleaned out the throttle body
• Multiple bottles of fuel system treatment (slick 50).
• Opened up the gass tank to check the fuel pick up
• Checked the vacuum line coming into the throttle body from underneath the intake manifold
• The air cleaner was recently replaced

There isn't any codes nor check engine light. Does anyone have any idea what could be causing the miss fire and consumption per liter not to be linear?