clogged egr port

EGR is used to lower combustion temperatures and in doing so lower NOx emissions. One benefit of having an operational EGR system is that it lessens spark knock/detonation/ "pinging" . To answer your question keep driving listen for "pinging" worst case change upward one grade of gasoline (higher octane). But chances are everything will be fine/ One of my customers put 465,000 miles on one engine in his Corolla.