Conditions for setting this DTC are as follows:
- Number of lean to rich counts is less than 15 or rich to lean counts is less than 10.
- Engine speed is 1600-2600 RPM.
- TP sensor angle is 8-20 percent.
- Purge learn memory is greater than 191.
- Evaporative emission control system is commanded open for greater than 60 percent Pulse Width Modulated (PWM).