How to fix P00089

Question

Engine always starts and runs but, it ocassionally suddenly loses power and will not rev beyond 3000 rpm, even in neutral.  Perhaps a second later or a minute it suddenly cures itself and it feels like theres more power than usual and you race off.  (this may be normal power but after having none it appears like more).

If I clear the code P00089 it stays inactive until the power loss occurs again.

This problem has progressively got more and more regular (not worse) worse,  It started with once a week for just a second or so to now being more than once a journey and lasting for a minute or so.