Hi. On the freeway my car wouldn't accelerate and dropped down to a slow crawl and it says reduced engine performance. I crawled all the way on the shoulder til the next exit then stopped and turned my car off. I waited a minute then restarted it and although the message is still on and the check engine light on too, I was able to drive normal the rest of the way back home. What do I need to do? Is this because I'm almost due for an oil change? Or the fuel sensor? Can I just wiggle something? How much will a repair cost?

 

You would need the car to be scanned to see why it went into limp mode. Restarting the car will take it out of limp mode, that's why it worked fine after.

 

My '12 xc70 just gave me this same msg for the first time tonight. I'm trying to figure it out! Not a super obvious resolution. Grrr!!

 

The reduced engine performance is the computer's way of keeping you from doing serious damage to the engine when a problem has been detected. There will be stored fault codes that triggered the warning which should be read by a diagnostic tool. If you want to read the codes on your own, you can buy a $30 OBD2 scanner at Harbor Freight or "rent" (usually for free) a scanner at Autozone etc. If your not that handy, book some diagnostics time with your dealer or Volvo friendly shop asap. It could be something simple like a mis-fire caused by a bad coil or an intake air leak, or it could be something more involved that if left unattended could cause valve or piston damage. Spending the $100 for the diagnostics is way cheaper than $3000 for a rebuild...

 

What year is your car?

It's has nothing to do with an oil change.

You can't just wiggle something (well you can, but it won't help)

No way to tell how much this will cost without a diagnosis. For instance if your car is a 2001 you might have a bad throttle module. But we don't have that info yet. As others have mentioned a scan with a compatible scan tool would be your first step.