Just had MY98 MOT. Straight through with no problems. But the day before it went in the car was misfiring driving to work. I requested this looking at, and £50 worth of diagnostics later the dealer has reset the ECU and ISC unit. Car seems fine, but does anyone actually know what the ISC unit is/does. The guy on the front desk at the dealers didn't know and I didn't have time to track down the mechanic.

Ric