can anybody help me?

[nickolley2k6]

iv just had a new exhaust fitted to my tf about 3 weeks ago and now for sum reason my car seems to be missing when im taking off. its not to bad in first gear but when u go up the gears it starts to shudder then slowly pick back up. i was told it could be the plugs but im not sure, any help would be great, thanx

[Byron]

could well be your plug's or a coil breaking down under load,sorry it's a bit vague but that's all i could think it being at presnet.