Good advice right here, Tony.I'd really be moving the tune up the priority list. If you're running lean, it could be a ticking (or popping?) time bomb. One good WOT blast could be the last. A good tuner would be able to see how it's running and what may be causing the pop. Fixing the issue (tune, fuel pump, injectors... whatever) rather than repairing it's consequences if left alone would be much cheaper. Until you know what's goin on, drive it easy.