92 Saturn SL2

Help needed. My 92 Saturn SL2 with dual OH Cam is acting up lately. Going up a long hill the engine seems to loose power and at times it stalls. This seems to happen only in the first 5 miles, after that everything seems to be OK (most of the time)Any suggestions what could be wrong???
By he way, after the engine started bucking and backfiring a mechanic told me to disconnect the EGR valve and plug the vacuum hose. That seemed to help, but I'm worried that it may not be too good for the engine
Any help would be appreciated

http://www.saturnfans.com/forums/showthread.php?t=24003

Thanks for the reply. I visited the forum and the thread and will give the suggested fix a try.
Thanks again, Lothar