Some news, car is at last running good ! No codes, no misfires everything is ok !
All the problems were caused by a faulty lambda pre cat on cylinders 1-2-3.
Engine is now fixed for a good time (4 lambdas, 6 coilpacks, 6 iridium sparkplugs, new waterpump, accessory belt ...) , runs well, E85 cost half a liter of gasoline here so it's now an econobox
