clio 182 cup
guys i bought the 182 cup a few months ago drove it for a while..took it to btm to find out it had the dephaser rattle so thought id drive it as it was rattling a little on start up any way. a few weeks later the car started to splutter on low revs so i bought new plugs and leads and fitted them which cured it but it still had a tiny hesitiation but very rarely happend. Now this week it sounds different on idle sounds lumpy and when i drive it it just splutters and hesitates in all the revs. what could this be? the exhaust is blowing too as the backbox has started to come apart. . when the car is cold it still sounds crap but dont hesitate when driving untill about 2 minutes later. then it just splutters and hesitates and just doesnt want to drive smoothly.once moving it sounds like a scooby.i was thinking could the plugs be gone AGAIN?or would the dephaset pulley cause this? please help as its driving me nuts now i feel like just getting rid of it but its a shame because i really liked it when it was ok..smells a bit too when driving it like a petrol sort os smell maybe all this is down to one problem along with the exhaust blowing. i had it on the diagnostic it came up as missfire..what could it be guys ????? please help id appreciate it!