I was having a repeated error code "Bank 1 too rich", which didn't seem to impact driveability, but was annoying. Then we started having an intermittent erratic idle and stalling out issue. When the tach fell below 1000rpm the car jerked and the tach would jump up to 1500 then back below 1000 a few times before stalling out. The fix for both was a new mass airflow sensor.

 

Good for you. What was the error code?