Check Engine- codes P0171 and P0243

Hello,
I'm new to this forum as I recently purchased a 1998 volvo xc awd turbo wagon from a private party. The day after I bought the car the Check engine light came on and a friend of mine with a code readed pulled codes P0171 and P0243 from it. The car stalled out while I was driving and now runs rough and hesitates and stalls frequently. I'm rather handy with cars and would like to attempt to fix it myself instead of sending it in to a dealer. From what I understand so far, message P0171 indicates the system is to lean and message P0243 indicates a turbo wastegate malfunction solinoid a.
Now, I'm confused over what actually I should be is broken and needs replacing. Any help or guidence is greatly appreciated!!!

Here is some info on the PO171 issue:

Upper Limit

ECM-262A LONG-TERM FUEL TRIM
UPPER LIMIT

Checking fuel injection system



Check intake system for air leakage according to See: Component Tests\Check For Air Leaks In the Intake System

Hint: Air leakage in the intake system can occur through the canister purge (CP) valve, the secondary air solenoid valve and power brake booster.

Start the engine and idle it for 10 minutes

Check the mass air flow (MAF) sensor by Read its correction factors. The value should be between 2 and 12

NOTE: There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information:


To access/replace the Mass Air Flow (MAF) sensor, See: Component Tests\Component Access/Replace Procedures\Mass Air Flow (MAF) Sensor, Replacing
Verification

Test drive the car according to the TRIP schedule, See: Monitors, Trips and/or Drive Cycle (Readiness Codes)
Do not turn off engine after test drive.
Connect the car to VADIS again.
Read off fuel trim status.
There should not be any faults when fuel trim is finished.

Was a fault detected?


Yes - Continue below.
No - Testing Complete.

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault tracing for this diagnostic trouble code (DTC) or make another attempt.

PO243 is a problem with the signal from the Turbo control valve. Depends on whether it's intermittent or permanant. Could be a short in the cable between the control module and the turbo control valve. Sounds like something for a tech. or a very, very experienced DIYer.

Good luck.

I hate to tell you that it is the MAF, but that is what was wrong with mine when I got the same code, also the day I bought the car.. I got the dealer to pay for it.

Should cost you <$200
I, too, do all my own work. If you don't have manuals, go to alldatadiy.com, sign up for your car ($15), and follow the troubleshooting instructions to the letter. tgrumaj seems to have provided the correct area of the instructions. Do his first, and if that does not cover it, alldata is exactly the text from Vadis.

OH, ps,
to read the maf correction factors, you need an advanced diagnostic OBD reader like OBD-2.com or B&B electronics auto... forget the name of theirs. See their website.

Thank you both for your suggestions. You nailed the problem on the head! The car had a bad MAF sensor. I tried my luck with one from a nearby auto salvage, and the car is now running beautifully. I had the Check engine light turned off and it's been off ever since. So for 5 minutes and $50 bucks later, I'm I happy camper. I hope any other future repairs are this easy!! Thanks Again!