P2387 indicates the EGR (Exhaust Gas Recirculation) position sensor 'E' circuit is reading a voltage lower than the expected range. The EGR sensor monitors the position of the EGR valve to help control exhaust gas flow into the intake manifold. When the PCM detects abnormally low sensor voltage, it sets this code and may illuminate the check engine light.
The sensor itself has failed internally, causing it to output an abnormally low voltage signal to the PCM.
Damaged, frayed, or corroded wiring and connectors can cause low voltage readings or open circuits.
A wire in the sensor circuit shorting to ground will cause the voltage to drop below normal operating levels.
Corroded or loose ground connections for the EGR sensor can cause low voltage readings.
If the EGR valve is stuck or binding, it may prevent the sensor from reading correct positions.
A failed or faulty engine computer is possible but rare; this is typically the last cause to investigate after all other possibilities are ruled out.
PCM failure is very rare for P2387. Most shops and parts stores incorrectly recommend PCM replacement far more often than it's actually needed. The EGR sensor, wiring, and grounds are the actual cause in the vast majority of cases.
Vehicle operation is possible but not recommended for extended driving. You may experience drivability issues, and continuing to drive with a malfunctioning EGR system can affect emissions and potentially cause engine damage over time.
Yes, because the EGR system controls NOx emissions, a P2387 code will typically cause a vehicle to fail emissions testing in states that use OBD-II inspection.
Repair costs vary widely by vehicle. A replacement EGR position sensor typically costs $50-$200 for the part, with labor additional. Wiring repairs can range from simple connector cleaning to extensive harness replacement depending on damage.