Code P0172 (Bank 1)

Can anyone tell me what this code is? I have a 98 Transport Montana. The SES light came on and I immediately stopped at an Advanced Auto to get the code read. It is off now. Is this something I should be worried about? I have a 1600 mile roundtrip coming up this week and want to feel confident about this van. I wouldn't want to be stranded with my wife and 6 month old daughter. Thanks everyone.

P0172
System too rich
(Bank 1)

'Fuel Trim rich' below is for 95 but should be similar...If you need more info , send me an email..
Paul
DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic charts.


Visually/physically checking items which may cause a rich condition may determine the cause of DTC P0172 being set.
A mass air flow sensor (http://www.alldatadiy.com/alldata/AFI~V6512274~C21327~R0~OD~N/0/41746505/42420118/42420119/42420121/34853741/34857029/34857030/56191599) that causes the PCM (http://www.alldatadiy.com/alldata/AFI~V6512274~C21327~R0~OD~N/0/41746505/42420118/42420119/42420121/34853741/34857029/34857030/34857300) to read a higher than actual air flow can cause a rich condition and DTC P0172 to be set.
Silicon contamination of the Heated Oxygen Sensor (http://www.alldatadiy.com/alldata/AFI~V6512274~C21327~R0~OD~N/0/41746505/42420118/42420119/42420121/34853741/34857029/34857030/34857572) (HO2S) can cause a false rich indication to be seen by the PCM (http://www.alldatadiy.com/alldata/AFI~V6512274~C21327~R0~OD~N/0/41746505/42420118/42420119/42420121/34853741/34857029/34857030/34857300). The PCM will then reduce the amount of the fuel delivered, possibly causing severe driveablity symptoms.