Could be fouled plugs, or even bad leads. I've had that behaviour
from both causes, as well as low-octane fuel. But first, check
that the leads (plug *and* coil leads) aren't burnt at the ends.
A bit of corrosion can cause all kinds of unpredictable behaviour
too, so check all the main electric circuits for anything that
might indicate intermittents or high resistance.

If you have to replace leads, consider spending a few $ extra for
Magnecore leads or similar inductive *wire* leads. You'll never
ever have to replace your leads again (*), and will always have a
better spark.

(*) I had a Magnecore lead fail after 8 years once, and took it
back to the dealer. He looked at me shamefacedly as he instantly
repaired it, apologising profusely that the end hadn't been fitted
correctly from the outset and it should never have happened. I was
super impressed, needless to say :-).

That said, there are *many* things that can cause your symptoms.
Hope you find it.

Clifford Heath.

There are a bunch of things that can cause hesitation or sluggishness.

Just as another example to add to what Clifford said, a bad Knock
sensor will cause your ECU to dial back on the timing causing some
major sluggishness. I have this happening to my car now, and it almost
feels like it goes slower the harder I press the pedal.

My wifes '03 H6 OBW is glass smooth at all times and a pleasure to
drive. heavier than my WRX for certain and a different type of drive -
but no engine related issues - so far(no VDC). Did you get a CEL? Wonder
what code it stored? When you floor it, did rpms go up but no movement?
Maybe it's a transmission problem?

let us know what they find.

Carl

I've never experienced any hesitation in my 05 OBW with that engine.

I've had some hesitation problems on my 2000 OBW 2.5L H4. I've recently
switched to higher octane gas, and it's smoothed out quite a bit. My
hesitations normally occurred during stop-light starts from a standstill.

    Yousuf Khan

Well, I had the Service Manager and several Tech's drive my car, they all
felt the hesitation, but, they all said it was "normal for this engine".
There is a firmware upgrade from May that is supposed to fix this, and, that
had been applied, but, obviously didn't fix it.

I have an appointment with the Regional Rep next Wed, so, we'll see what he
says.

I can't believe that they can't fix this, and, in fact several of the Tech's
told me that that's the reason they bought the 4-cylinder Turbo model,
instead.