P0401 CEL, low rpm/misfie when idle

[meGrimlock]

lately i've been noticing that when the car is idle, the RPM will stay around 700RPM. then the car will misfire and then drops to < 500 RPM but never stalls. this rarely occurs but when it does it will do it for the whole day. from reading the forums it seemed like symptoms of the dreaded EGR valve but it wasn't throwing a code.

jump to last week when i got my first check engine light in a year or 2. code is P0401 Exhaust Gas Recirculation Flow Insufficient Detected. i did some light highway and moderate city driving for 2 days and the code went away.

is this something urgent to worry about since the code went away on its own? or should i still troubleshoot the EGR valve/boost solenoid/etc as the FSM states? my biggest concern is passing state emissions inspection, coming up in a few months.

here are the details i pulled from the OBDII port:

View / Vehicle Trouble Log / Problem 1

Overview

• Time 27/07/2011 08:53
• Trouble Code ... P0401
• Description ... Exhaust Gas Recirculation Flow Insufficient Detected

Engine Status

• Fuel Pressure (Gage)
• Intake Manifold Pressure (Absolute)
• Engine Coolant Temperature ... 359.15 K
• Calculated Load Value ... 11.0 %
• Engine Speed ... 47.18 Hz
• Vehicle Speed ... 21.4 m/s

Fuel Trim Status

• Short-Term Fuel Trim (Bank 1) ... 0.00 %
• Short-Term Fuel Trim (Bank 2)
• Long-Term Fuel Trim (Bank 1) ... 1.56 %
• Long-Term Fuel Trim (Bank 2)

Fuel System Status

• Fuel System 1 Status
• Fuel System 2 Status ... Open loop due to driving conditions (power enrichment, deceleration enleanment)

thanks for any advice