Hiccup when cold and lights dim etc.
 

A friend of mine has a 2002 V70 2.4T (95k miles) that is having some issues. I couldn't figure it out, so I was hoping to get some suggestions. No warning/check engine lights yet either. Here is the best description he could give (all services are up to date on the car as well).

Has a "hiccup" in the idle until it's been driven a while. Almost like it is going to die, the lights dim and the dash lights dim for a second. Not noticeable after its warmed up. A result of not being driven?

Thanks for the help

Does it happen only when slowing down or reving and letting of the gas?

If so try cleaning the throttle body.