Problems at high revs

[ViaraiX]

EDIT: Forgot to say, 2000, T6, 122k on clock

Recently had a problem appear at high revs (happens every time).

At about 4800-5000 rpm it pauses for a few seconds (as if I've taken foot off accelerator) after about 2-3seconds it will then rev higher and emmisions light then begins to flash.

Read the codes, only code that comes up is P1152 but tbh I've had that coming up since I've owned the car.

Had similar problem before where it would judder around same rev range but had a misfire code showing which a plug change fixed, the plugs where changed about 2 months back so cant see them needing another change.

Any ideas?