This garage is having your pants down , if they have changed the intake they could of cracked the little pipe that connects to it which causes misfires, I would personally , get £40 worth of spark plugs in it gapped at the correct mm and take it from there 

11 minutes ago, thomasaspin said:

This garage is having your pants down , if they have changed the intake they could of cracked the little pipe that connects to it which causes misfires, I would personally , get £40 worth of spark plugs in it gapped at the correct mm and take it from there 

They changed the spark plugs about a month ago during a major service 🤔

More than likely the wrong plugs have been fitted during your service.

On 07/09/2021 at 19:24, VRSFABIA2021 said:

They changed the spark plugs about a month ago during a major service 🤔

Just because they say they have changed then 

1 doesn’t mean they have & 2 doesn’t mean they have used the correct spark plug and gapped them correctly which is crucial in these engines