Had exactly the same problem with my s40 t4. Check for cracks in the ignition coils, Clean the sparkplugs and the idle Control valve.

edit : The same lights would come when the car was stalling. Tho I wasnt able to read the codes at the time, and they didnt apear in "stored" in Vida Dice.

Sounds like the idle Control valve is bad, also check your ignition coils for cracks. Had the same problem with my s40 t4, but it would also die randomly while driving due to the cracks. Replaced the Idle Control Valve today and now the car runs great!

Hi! So I recently got myself a Volvo S40 T4 2002, 160.000km.
When I test drove the car everything was fine, making 1.0 - 1.2 bar of boost, no stuttering or anything like that.
Once I was making my way home with the car it started stuttering etc and died once I engaged the clutch.

The problem with ...