[HotSpicyChicken90]

Hello guys.

I'm back again...

I finally found the REAL CULPRIT!

IT WAS THE CHARGEPIPE O-RING...The pipe itself was not securly atteched 100% to the intercooler and the O-Ring was fitted so lose inside the pipe that it wound up on itself. Since i didnt have a new one, i removed 2 cm from the O-ring and glued it together with crazy-glue. It is bomb-tight now.

Also pay attention to the orientation


Now it makes sense...
Since air escaped from this seal, less amount of air entered the engine, hence P0172 "system too rich". Means either too much fuel (or in my case) less air detected by the 02 sensors.