Oldsmobile/Buick Repair: vacuum purge valve, misfire codes, vacuum purge valve, buick park avenue

Question
1997 Buick park avenue w/Service engine soon light.  Code says vacuum purge valve.  Elected to continue driving. 2000 miles later, The engine sptters, acts like not getting enough gas or air flow, then strainghtes out for a mile. Then when cranked sputters badly, goes dead and will not crank.  Code reader gives same vacuum purge valve code and new code says random cylinder misfire.

Is the purge valve likely the cause of the misfire?  How difficult to change?  Other suggestins?  

Thanks much.


Answer
Hi
Purge code COULD cause the misfire code, but not likely.
I honestly believe you have another problem causing the bad running and the misfore code.
Check your coolant level. If low, I would HIGHLY suspect the upper plenum leaking coolant into the intake and conversly into the cylinders.
Also check time for tune-up, eg...plugs, wires, fuel filter, air filter.
Please follow back post, if needed.
Thanks
Pawl