Cavalier ECU problem?

Hi,

I was going up the A9 the other day (which was unbelievably busy, as usual). A rare chance to overtake came, so I dropped down to 3rd and booted it.

Just as I got level with the car I was overtaking something strange happened. It was as if the engine had cut out for a split second. There was a sudden decelleration, then it picked up again. It can't have lasted more than 0.25-0.5 of a second.

The car seemed OK for the rest of the journey. In fact, dropping down into Inverness it was running away from me. The reason for this became apparent when I tried to drive through Inverness. The engine was idling at just over

Being employed in IT, I know the answer to any problem is to reboot it , so I pulled into a carpark and switched off. When the engine was restarted it ran OK.

Any ideas why? Is it a sign of an impending failure? It was raining a bit, but nothing torrential.

While I'm asking about the ECU, I have another query. I'm regularly getting around 40mpg, which is great for the environment, but I think a little more power wouldn't be a bad thing. Is there any way to make the ECU more sporty (other than chipping it)?

Car is a '95 (M) V6 Cavalier, by the way.

Thanks,

Iain