My v70 is reading the code p0305 and says slow down or upshift.
The car runs rough, has little power. The p0305 code means cylinder 5 misfire, but it is the 2.4l 4 cylinder.
Any suggestions?

 

You should recheck the engine for the number of cylinders. As far as I know the 2.4 LT is a five cylinder.
I could be wrong though. It happens.

 

pop off the the spark plug wire cover, #1 is closest to the timing belt. #5 is by the bell housing. You can start by replacing plugs but the coil pack is also a likely suspect. Also look closely at the connector to the coil. If you are not sure about the coils, try swapping say 3 and 5 then see if you get a 303 or a 305 code next time.