The fact you have 3 cylinders misfiring means it’s an upstream error that’s affecting all at once.
Quite probably as @colb says an air leak. You need to look round all the rubber in the engine bay and track down where it is. I would start with the hoses that come out the back of the air box and into the engine. But for sure you need to attend to the issue @colb has pointed out too - which might be your only issue.
Quite probably as @colb says an air leak. You need to look round all the rubber in the engine bay and track down where it is. I would start with the hoses that come out the back of the air box and into the engine. But for sure you need to attend to the issue @colb has pointed out too - which might be your only issue.