I've recently noticed that when the weather's quite foggy / misty / damp, the car can feel very hesitant in acceleration.

I think it mostly happens in 2nd / 3rd gears, when it just feels flat and could potentially stall when in first.

What could be causing this and what would need replacing?

When I do get going and try to apply some gas, you could hear tickety clicks and maybe some slight whistling (I think coming from the exhaust system).

Thanks

Edited by clappedout on 18/12/2017 at 13:24