I had exactly the same fault on the same model after a Foolparts coil pack was fitted (NOT BY ME!). Oscilloscope connected to injectors showed interference from coil pack on road test. This showed as an extra spike on the earth line of the injector switching. Sorry, I didn't keep the trace.
I also understand that this, if left to continue, can spike and ruin the ECU. As already said, get a genuine coil pack on it, Quick! Regards, Gwyn