Volvo Repair: Hello Volvo Gurus ! I am..., volvo v70, accelerator pedal

Question
Hello Volvo Gurus !

I am quite despered with my prob. I will try this also.
(So I am from finland -> sorry about bad english ;-)

Prob.
My Volvo V70 2.4T model 2000 "old body"  automatic
has broblem that it some how lost power with steady speed ~110 km/h
it feels like "driving agains strong wind that comes behind forest" (hope that you know what I mean ;-)
then it may go some while without twitch... and again twitching... and so on..

I have used some gas additive for cleaning injection system (could this be the reason for prob.)

I have changed sparking plugs & air filter...
and because car has some kind of straight ignition nothing else that I can do with ignition...
Also failure codes read in Volvo care ->
no any failures found (also there they do not know what may be wrong)

Thanks in advance ;-)

 -  EsaS  -

Answer
unfortunately on this type car there could be many possible causes, but most of those should give some type of code.most common problems on these cars would be a bad air mass meter or bad electronic throttle module.I have also seen the accelerator pedal sensor go bad which is part of the gas pedal assembly.without the problem happening and being able to check the signals of various components you can not be sure the exact problem.sorry I could not help more