Low Boost

[CalLook67]

So sometime in the last few weeks, my '06 US 9-5 has lost a fairly significant amount of boost at WOT, and I'm at a bit of a loss as to where I should start looking for solutions. I don't know exactly when it started as I don't have a commute that really allows me much time at full throttle, but today I noticed that the turbo gauge only shows about 2/3rds between neutral pressure and full boost at WOT and the car definitely doesn't accelerate as hard as it used to. There hasn't been a Check Engine light, there are no weird noises on boost or otherwise, and the car seems to be running totally normally other than at full throttle. A quick glance-over didn't show anything super abnormal, but it was hot and I didn't feel like poking around a warm turbo this afternoon, so maybe tomorrow I'll ride my bike and check the car out after work, but in the meantime I'd love any kind of directions as to where I should look.

[CalLook67]

So after a few days of researching online, I tried cleaning my MAF sensor and that immediately worked. There was nothing loose, nothing off, it just wouldn't boost as much as usual, and a quick clean of the MAF did the trick.

[Dave T]

I fixed a BMW X3 (E83) that had a check engine light on. Spraying the MAF with cleaner made the light go away. It didn't go off immediately but after about 25 starts over many days.