I have a 2000 S70GLTSE. 57,000 miles.Been a great car. Runs fine,
but while maintaining a constant speed, say above 50mph, it will stutter
intermittently. Dealer replaced fuel filter (60,000 check) and then
the mass air-flow meter, got new plugs also. All liquids are good. I ran
the 44K stuff in attempt to clean injectors, no change. I ran cheap gas
for 4 years. Maybe carbon buildup ?

Help....then I'll take to someone other than DOn Buyer Volvo.

Jim

Try replacing the spark-plug cables. They may be too old
The best thing to do when you can't locate the problem is to start replacing the most in-expensive parts first.