Quote Originally Posted by Astro14 View Post
There are several possibilities. MAF is one of them. Cleaning it might help. It might not. Sometimes, MAFs go bad...

Guessing isn't really a good method of troubleshooting. Get the codes read, preferably by a VIDA/DiCe machine and someone who knows Volvos.

If this car is new to you, then baseline it. Change fluids, filters (oil, air, fuel) and spark plugs.
Amen.
Throwing lots of parts at a problem will bankrupt you, and not help the car...I know.

It is possible that even a cheap code reader or the "free read" at neighborhood auto parts store might tell you the problem.
But it might take VIDA/DiCe...

Could be any one of a plethora or items: a cracked vacuum hose, fouled PCV system, an intermittently failing coil, fouled plug, bad gas, stopped up fuel filter, one of many sundry sensors failing, plugged injector, etc., etc...