1.2 TSI 2015 2096 error code

Hello,

got a 2015 Fabia with the 1.2 TSI CJZC engine.

about 2 months ago orange engine light and a 2096 error code with is the lambda sensor down stream of the cat.

only bought the car in July last year from a Skoda dealer hence it was fixed under warranty (they just replaced the sensor).

1 month ago same issue and whilst waiting for Skoda to get yet another sensor the car went for its MOT and failed on emissions  (high CO).  Garage says over fueling and cat might be damaged.

back to Skoda.

They now say that the post cat sensor needs replacing again but also the ‘vacuum sensor and pipe….).

I asked if they meant the MAP in the pipe between the turbo and the inlet manifold but they were insistent that it was a vacuum sensor….

is there a vacuum sensor on the induction system ??  If so where and what does it do?

as it’s a turbo charged engine the inlet will be running above atmospheric pressure (rather than below for a NA engine).

any help gratefully received,

have a good one

Dave