Reinstalled index 12 injectors on cyl 1-3 (because we tested with index 6 earlier today). Index 12 injector from cyl 2 was moved to 1. And index 12 injectors from cyl 1 and 3 were reinstalled in cyl 2 and 3 (order not recorded) New downpipe gasket (bank 2), nothing else was changed related to bank 2. Tightened loose spark plug (no2). Made sure all other plugs were tight. Ambient 32C / 90F humid Probably mixed 90% RON 98, 10% RON 95 in tank.