2002 S60 T5 has a "stutter" when the turbo kicks in
 

The car seems to run fine until I get it up to 2800 or so RPM. If I get on the gas hard the car has a "stutter" and runs rough until I let off the gas. Any help is greatly appreciated.
Beau

sea foam great place to start heres a you will get the idea http://www.matthewsvolvosite.com/for...hp?f=9&t=30650 . There could be built up.Check Plugs also and replace if ther are older that 30,000. Also check trany fluid color and smell> If it brown-black replace it .

start with stage 0 tune up, plugs, fluids, even coil packs, fuel filter, throttle body cleaning (dont spray into it, take it out and clean it with a rag and carb cleaner)

I pushed it hard into the "stutter" and got a check engine light. It was a missfire on cylinder 1, so I went ahead and replaced that plug. No missfire on normal driving. I pulled the MAFS last night and cleaned it. I'll drive it this morning and see how it does. Thanks for the help. I'll post later with results.

Well cleaning the MAFS seemed to help some but definitely didn't fix it. Could a vacuum leak cause this?

it could i think yea, mine used to stutter at idle occaisionally and my whole car would vibrate and rattle --> then i changed out my coil packs for the new IPD HD ones and no more rattle, no more stutter, engine runs smooth. If your getting a check engine light when under accel. it does sound like a misfire, could be you have a coil pack failing. when my MAF went on me it acted funny for about 3 days before it finally quit

these cars can be picky when it comes to spark plugs
at high boost it tends to blow out the spark so every 15-20k miles take out your spark plugs and regap them
and every 60k change them (i change them at 30k they are cheap and i like doing it lol)

Replaced #1 coil, then the Seafoam. 1/4 in the crankcase, 1/3 in the tank and 1/3 in the intake. HOLY CRAP!!! I can't believe how great it runs. Smooth, powerfull and OMG it just feels great to drive again. If anyone has questions about what I did, I'd be happy to help.
Beau
S60 T5

Maf sensor problem?
 

I have owned a Volvo S60 2002 for over 5 years. A couple of years ago while driving on the freeway the car lost power and the check engine light came on and the message "Reduce Engine Performance" as well, after turning the engine off for 10-15 minutes car ran fine again. Three weeks later car stalled again; took it to the dealer they replaced the throttle module and car ran fine for a couple of months. A couple of months later the car gave me the same problem, took the car back to the dealership and they could not find any problems, they suggested me to replaced the main system relay, I agreed since the relay was only about $28. The car keeps giving me the same problem and I am really frustrated, I keep taking the car to the dealer and they can not find any thing since the symptoms do not throw any codes. My trust in Volvo cars is rather shaking. I have read posts in volvo-forums that suggest that it is possible that the mass air flow sensor might be failing or the Oxigen sensor. Do you think that this also has to do with spark plugs? Any recommendation will be very well appreciated.
Sincerely:
Really frustrated volvo-owner.