Mine had the loud popping noise and finally died on the side of the road. Got it towed home and took out the opti and tore it apart and what do I find???? The rotor button came unscrewed and was just laying at the bottom of the opti. Nice I know, just something to think about. You can always take it to a shop and have them check your fuel pressure pretty cheap. If you have bosch plugs THAT IS A MISTAKE, they DO NOT work well in LT1's, get the AC Delco plugs that are recommended for your year/model !!!