I have a fiat punto 1.9 jtd punto mk2 2003, I have had this car for about 8 months but I need some information on it. Right one minute the car is quite then next minute it sounds like the air box is off and sounds like a tractor somedays like I say it quite and when it's quite it feels much quicker than it does when it's noisy really weird problem! Yesterday the car felt really nippy and it was quite but today she's a tractor and very gutless 85bhp model. I have checked for exhaust blows and checked air filter box but that's as far as it goes! Any ideas would be APPRECIATED!!! Thanked