Re: 146 ti misfire
Variator won't cause a misfire, but it could be the plugs. Easy enough to do if you've got the right torx fasteners, just remember that they may have been in a while; I squirted some plus gas into the recesses and left it overnight to minimise teh risk of snapping them off. You'll need a long reach spark plug socket, 14mm IIRC. You might also find that there is oil in the spark plug recess from a weeping cam cover gasket, if there is I would clean that up and see if it helps before worrying about the plugs.