This morning my malfunction indicator light was on, not flashing though. So after doing a little research here I did the ignition key test to find the code(s) being thrown. The code was P0404 - Egr Position Sensor Rationality Open. Could anyone explain what this exactly means? Would it be ok to still drive on it for a couple days til I can get it in?

Thanks in advance.

You will notice most of the troubleshooting involves electrical faults. ("Possible Causes", below)
Most people, however, report changing the EGR valve has corrected the problem.
It won't hurt to drive it for a short time.
A steady MIL is not as urgent as a flashing MIL.

This is from the service manual:

Theory of Operation


The EGR valve has a position sensor and the EGR position rationality is designed to make sure that the valve moves freely within its operating range. Closed valve position reference check verifies that the valve is within its allowable upper and lower limits. The EGR position rationality test looks for a sustained error relative to commanded valve position.

• When Monitored: Engine running.
• Set Condition: The EGR flow or valve movement is not what is expected. A rationality error has been detected from the EGR Close Position Performance. Two trip fault.

Possible Causes
EXCESSIVE RESISTANCE IN THE (K34) EGR SENSOR SIGNAL CIRCUIT
EXCESSIVE RESISTANCE IN THE (F856) 5 VOLT SUPPLY CIRCUIT
EXCESSIVE RESISTANCE IN THE (K35) EGR SOLENOID CONTROL CIRCUIT
(K900) SENSOR GROUND CIRCUIT OPEN
(Z906) EGR SOLENOID GROUND CIRCUIT OPEN
EGR SOLENOID ASSEMBLY
POWERTRAIN CONTROL MODULE (PCM)

I had a EGR Sensor Circuit A High code and drove it for a long time--probably 15K or more miles. When I finally got around to changing the valve, it smoothed out the acceleration at low RPMs. Very noticeable difference. Changing the valve is a pain--it's located on the back of the passenger side cylinder head. I wrote up how I did it (by removing the fender). If you decide to take this route, get the correct fasteners from Auveco beforehand (order through clipsandfasteners.com). And order the valve itself from Wyckoff Parts Online (a forum sponsor). Those two hints can easily save you 20-50 dollars (depending on how hard you are on those fender clips). Here's the write-up ...

EGR Valve Replacement (DTC P0406)