Probable Cause

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

For DTC P1227: An excessively low voltage from the APP sensor 2 is sent to ECM.

For DTC P1228: An excessively high voltage from the APP sensor 2 is sent to ECM.

NOTE: When the malfunction is detected, ECM enters into fail-safe mode and MIL turns on.

ECM controls electric throttle control actuator in regulating throttle opening in order for idle position to be within plus 10 degrees.
ECM regulates an opening speed of about 5 seconds for 10 degrees. As a result, acceleration will be poor.