v6 running problems

[Col]

A while ago my v6 began to run really badley.
massive loss of power and the ecu light came on and stayed on all the time.
First point of call was plugs and leads - replaced but no change.
in doing so realised she was only running on 4 cylinders.
stuck a new coil pack on but again - no change.
next i tried a new ECU - no change
lastly, changed the ignition amplifer module.
now runs on all cylinders fine (and ecu light has gone out) but still no power, she hardly moves and sounds terrible.

so to summarise:

new plugs and leads
new coil pack
new ecu
new ignition amplifier module

still runs terrible and hardy moves

any ideas anyone ? cars sat there as i dare not try a jouney incase she conks out

thanks in advance !

[trev150]

Have you read off the fault code from your ECU?