Vehicle: 2001 Pontiac Grand Prix, V6-3.8L, VIN K, Automatic Transmission/Transaxle
Problem: This vehicle came into the shop with DTC P0404, which set right away after clearing. The customer noticed the engine stumbled on mild acceleration.
Details: The EGR valve could be commanded open with a scan tool. The engine only stumbled at idle when commanded to 60 percent. The technician removed the EGR valve and inspected all ports. All ports were clear. Scan tool PID information showed that the EGR position voltage was only 1.75 volts when the valve was commanded to the wide-open position. The voltage at the sensor matched the scan tool data.
Confirmed Repair: The technician replaced the EGR valve. Now the position voltage reached 4.25v at the wide-open position. The DTC was cleared and the vehicle test driven. The problem was resolved.