I have a 91 Previa LE RWD that has an engine light on. I saw Tim's thread about jumping the diagnostic port to check for codes a toyotavanpeople.com. It flashed seven times, then once. Code 71. According to Tim's post with a picture of the codes listed, I shows the EGR System malfunction. EGR Valve or EGR Hose or EGR gas temp sensor circuit or EGR Gas Temp Sensor, or the ECU.

Is this something that needs repair right away?
If you suggest repairing it is there a page with the correct procedures available?

I'm about to take this previa on 2000 road trip and want to make sure I don't have any problems.

Many Thanks,
James