Well, it happened yesterday.
CEL came ON but there was no change in performance though.
Hooked up the scanner and got 1 code P0420.
Immediately went to auto parts store and got new Autolite spark plugs and jumped on replacing all four plugs.
Spark plug holes were dry and no trace of oil.
Checked for vacuum leaks and all is well.
Reset the CEL.
So far P0420 has not come back after 100 miles.
Crossing fingers for code not to come back.
