Sounds like you might be a victim of foul play. My friend's boyfriend once poured sugar in her gas tank just to spite her after she dumped him. After much head scratching and testing her mechanic finally diagnosed the problem and told us about other ingredients people use to foul up other people's cars just to get even. At 47,000 miles having all your fuel injectors go bad at the same time is very suspicious. I'd have your gas tested for impurities if I were you. See if you can safely collect some gas in a clear container and examine it for color, smell, impurities and quality etc. This is an easy first step to check. If an adversary of yours knows that your a stickler for using quality gas this would attract them to mess with your gas because they know its a good way to get you pissed. Sorry about being a cynic but you can't dismiss the possibility of foul play under the circumstances.