Runs rough with a new brain

The most common symptom is the idle speed will be too low until the new computer relearns "minimum throttle". Until that occurs, you may need to hold the accelerator pedal down 1/4" for the engine to run. You won't get the nice idle flare-up to 1500 rpm at start-up, and it may tend to stall at stop signs.

To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals.