200k mileage and your worrying about a few bhp!
some engines would be dead at that...
get the cam timing checked/dialled in new plugs and & quality oil in and enjoy it :chris2:
usually to cause stalling it will be loss of something major....fuel pressure or crank signal....or timing belt failure
blowing exhaust or loose coil will only cause rough running/mis fires etc
i usually recommend cleaning off with brake cleaner and this then will show you were it starts leaking from...
be careful with the vvt seal as i think they are not that easy to change...been awhile since i had my hands on the f4r