Hi chaps
Ive got a 89 series 2 running mfi, a uknown chip and 12psi boost on standard cooler.
Ive got a hesitation/stutter on boost in 3rd 4th and 5th gear, I fitted a wideband afr gauge and my readings are

Light throttle/cruising :between 12.5-13.5
On boost :between 13.5-14.0 sometimes 14.2
When I come off the throttle the gauge goes straight to 22.9 untill it reachs about 1800rpm it then starts reading afr again

So my question is do these reading seem ok and any idea what the.hesitation could be
Ive been to 3 different tuners now and they keep taking my money and telling me its fine but it isn't
Any ideas much appriciated
Mick