My car has a cough (see video)

[Nicka]

Hey guys, Another problem I need help with.
I have a Volvo S70 2.0 petrol auto. It's really hard to explain which is why I have uploaded a video, but the car is coughing whilst accelerating. I have changed the fuel filter, air filter, spark plugs and ht leads, but the problem still persists. By changing the HT leads, it did make a slight improvement, but didn't fix the problem. I have also checked for any air pipe leaks, but all seems ok. The throttle body has also been cleaned with carb cleaner.
Now the funny thing is that it drives much better in sports mode rather then the (E) economy mode. Any suggestions would be great.

Sorry for the poor video quality.