Mine has started recently setting the P0243 (wastegate solenoid malfunction) code occasionally, which means no boost and it makes the car too slow to merge onto the freeway safely (ill-advised metering lights mean merging onto the freeway is often a full throttle 0-75 mph exercise to avoid getting run over by a semi truck in the places I regularly drive).

But anyway, from a google search there are so many things (MAF, waste gate solenoid, actual wastegate, catalytic converter, egr, various vacuum lines, etc) that can cause this I could probably buy another car for cheaper than just replacing stuff until I guess right. Has anyone has this happen and actually fixed it? I have found that with most extremly hard to diagnose problems asking someone else how they fixed it is usually the best place to start.