Hi,Vauxhall 10 plate old shape has developed an engine judder and has code P113 error code,local garage tells me is maifold problem and is common fault.He advised me to contact dealer that I bought it from as is common fault,car has gone 2 months over its 12 months warranty.Dealer has said if common fault we will fix it if not you will have to pay (won't be cheap!).Can anyone confirm if it is a common fault please and if so,how I prove it!

Thanks.