A bit of a odd problem with my 2002 UK Voyager. When the car gets hot when stuck in traffic it always sounds like it is going to cut out although it never does. Then a few weeks ago it developed a really rough idle and I got code p0303, this cleared itself after a few days and then I started to get a 'Knock' a bit like a misfire when pulling away. Took it to Chrysler who said they could find nothing wrong, told it could not be the ignition leads or coil as that would throw a fault code up, they suggested possible spark plugs or just start to run the car on premium unleaded rather than normal and to stay away from supermarket petrol as it is not so good !.

Could it just be the fuel ?.

 

I realise this is an old question but I have recently bought a 2000 3.3 Voyager with exactly same problem. Does the solution as given by Chrysler re premium unleaded seem reasonable? I have already changed the plugs and leads on 2, 4 and 6 but 1, 3 and 5 look like proper pigs to get at. How do you reach them without unbolting half of the top of the engine?