Backfiring issue

I'm of the school of kiss... On these cars it's always something simple....
Only way it could really be something catastrophic is if it has to do with the cam or the valves... Like not putting oil with zinc in it and starting to wear things out over the last 8 years?...
agree for the KISS theory. I am sure once i get it figured out i will kick myself. as far as the oil goes, i have been running mobile 1 in it since i bought it.