part throttle hesitation on 2.5T engine

[NDT]

All,
I'd be grateful for any help.
Our S-Max 2.5T (which develops a new fault every month or two) is now hesitating at light throttle.
Idles ok, pulls like a train at mid/full throttle.
No fault codes showing up.

Independent garage says it doesn't feel like a coil pack going.
Waiting for a dioagnostic check at the Ford dealer.

Any thoughts?

[NDT]

New plugs a month ago.

[NDT]

New plugs a month ago.

[NDT]

Ford can't find anything wrong with the car.
The only stored code is PO61A - PCM Torque Performance.

[NDT]

Thanks - assume you mean a small air leak is throwing mixture off at part throttle?

[NDT]

Thanks guys.
Might be a job for the weekend to check those out.

N

[NDT]

ST GOZ said:

Sounds like your boost solenoid is sticking, very common on the Focus ST, if it was plugs the hesitation would be under load when the plugs are being stressed.

The problem is off-boost.
We had the boost solenoid replaced a few months ago - it was sticking open and causing overboost.

[NDT]

Cleaned MAF sensor - made no difference.
CO is spot on at idle so assume it's not the lambda sensor.

Any other thoughts?

[NDT]

edition said:

Did you manage to sort this issue?

In the end I stuck a used MAF meter on it and it fixed it.