Ok.. Here is my story so far
Get the car , runs perfect except for the 4,500- 5,500 misfire under load..
I put in a new set of plugs over the weekend, champion double platuim plugs with a 1.1 gap
Also did a oil and oil filter change on the car, Genuine filter and Repsol 5W/50 full synthetic oil.
Take the car home from doing all the work , hit the freeway and the car struggles when it gets up to around 80km/h + like it feels like someone has thrown out the ancor and im pulling it along.
Just wondering if anyone else has had this problem. Car is totally stock aswell!
Cheers
Mick