Opel corsa 2012 engine management light

SteveAdti

Would appreciate some help .
Engine warning comes on amber . I disconnect battery after 1000 kms it comes on again .
I bring to my mechanic who I get the impression doesn't know the car very well . Diagnostics say fuel trim . Resets light and says probably bad fuel.
Light come on twice since and caught the Rev counter hunting between 500 rpm and 900 rpm .
Did this for about 1 min and then engine light again .
Also revs sometimes not coming down from 2000 rpm when revved . Stays there for about 5 seconds .
I feel it's the Mass airflow sensor but would appreciate advise .
They are 165 plus vat from Opel and more from motor factors
Any advise would be appreciated
Thanks

porsche boy

get a second opinion from a different garage.

An Caislean

Any dodgy Petrol put in the Car at any stage i.e. "Petrol Stretching"?.

porsche boy

Go to a different mechanic.

George Dalton

Fuel trim code plus hunting at idle would suggest an air leak somewhere.

Spend money on a proper diagnosis rather than buying parts on the off chance.