Originally posted by webguyIS:
It's the main "brain" of the car. Controls things like fuel mappings, electronics, and handles all the input from the various sensors around your car. It's known as an "Engine Control Unit", hence ECU. I believe http://www.howstuffworks.com has a good bit on it, they're pretty damn good at explaining things.
That seems to be the general consensus, I'm not too sure though since I don't drive an IS. =(Originally posted by old dude:
Thanks much for the answer. I take it this is what causes the hesitation that many are ecperiencing when they tromp it?