I have a 2001 Insight (5 speed manual) that went in for service on Oct
of 05.  The main battery pack went out and it took 3 weeks or so to
replace.  After getting the car back it sputters when driving at a
constant speed.  It feels like it is misfiring, even though that is not
the case.  After taking the head mechanic on a test drive, they hooked
it up and found nothing wrong.  With no lights and no problem codes, as
far as they are concerned, there is nothing wrong.  One possible
problem they suggested is that I don't drive my car 'hard enough' and
there is a carbon build-up, which is my fault.  Ok... so the manual and
all the fancy computer components and lights that tell you how to best
drive your vehicle are wrong???  Anyway... I digress.  Has anyone had a
similar problem and, if so, what was the issue?  Possible suggestions
(oxygenated gas, wrong oil, etc) would also be very helpful.

Thanks all,

Michael