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