I own a reasonable good S60 2004 w/ 170k miles

My problem is a loos of power at speed from 55 and up.

Car was stuttering (nearly stalling) on acceleration from a full stop and replacing the spark plugs and the air filter seems to have corrected that problem. But I am still having the low power at highway speeds.

The engine seem to stutter as if one or more cylinders was not firing (very mild).

I am thinking this is the fuel pressure sensor located on the fuel rail.

Any help would be greatly appreciated.

The car is not indication any trouble codes so far. I have a scanner tool and keep getting the no codes present indicator.

Thanks in advance.

 

replace fuel filter, it may be clogged

 

There are several threads on this site that have this symptom in it. If you have a graphing scanner look closely at the ETM for loss of voltage when it happens. It will not throw a CEL unless it is broken.