The EGR Valve can malfunction causing a hesitation when accelerating, rough idle, or idle hunting (surging or idle going up-and-down). If the valve malfunctions, there may or may not be a Check Engine light.Google+
Car Problem Reports
Nissan Sentra Hesitiation or Rough Idle Due to Faulty EGR Valve
Nissan Sentra Problem
Model Year Affected: 2002
Engines Affected: 1.8L 4 Cylinder, 2.5L 4 Cylinder
Average Mileage: 125,666 mi (110,000 mi - 140,000 mi)
Visitor, 2002 Nissan Sentra, 110,000 mi
I've had the erg valve go bad twice on the same 2002 Nissan Sentra, back in 2006 and again this year.
Visitor, 2002 Nissan Sentra, 2.5L 4 Cylinder, 140,000 mi
Hesitation when starting..
Visitor, 2002 Nissan Sentra, 1.8L 4 Cylinder, 127,000 mi
still happening. Seems to have happened right after head gasket repair 4 weeks ago. mechanics can't seem to fix the rough idle. CEL was on and said egr... but then they checked egr and said it was ok and CEL stayed off