[Es2] Boost mystery

[Brandon Hull]

So I failed inspection at my local garage in my trusty eS2, and they put
in a new O2 sensor.  I drive the 1.5 blocks home from the garage, but
immediately notice that the cold stumble at idle is gone.  That's nice I
think, wonder how long I needed a new sensor.  The car sits for a week,
then my wife has to use it for a Sat trip to NYC.  How'd it run, I ask,
she says:  I tend to forget how fast it is.  Yup, I think, it's sure run
rings around the eurovan.  Then I drive it today to a meeting 15 miles
off.  Holy boost batman:  I'm getting 20lbs in each gear.  It doesn't
hurt that it was 49F outside this am, but it's never done this.   Have I
had a bad sensor for six years?  Has something bad happened and I'm
about to start blowing hoses?  Wow is it fast like this, and maybe it's
my puritan heritage but I'm unable to feel completely good about it...

Brandon