looking for some answers and going to give as much info as possible. about 2 weeks ago, i was getting off work and started my car to let it warm up. while standing on the outside of the car, i heard it idle really weird like it was stumbling. well I began to drive it home and noticed it felt a little under powered,but pulled strong. as the day gone on, the car was getting worse. i was running errands then i threw a cel. got it read at advance to the tune of my car was running lean (two codes said the same thing like at idle and i can't remember them off hand sorry) the car was obviously running pig rich at idle. the smell would burn your eyes!! black smoke accompanied this. took the advice of a friend and poured some octane booster thinking i got some bad gas. well a day and half later, the car returned to normal idle and seemed to drive okay. i went on vacation for 6 days and the car sat at the airport. drove it home and it was fine. well the other day, i decided to go WOT and hesitation and backfiring started.pulled the plugs and they were a rusty color(probably from the octane booster?) the gap remained the same as they was before. they are 1422's. mods are in my sig. now the reason i suspected bad gas is because the car was running great and pulling hard with issues, then out of nowhere with a full tank about a day after i filled up, this happens. going to replace my plugs tomorrow(i should be able to get a refund on them at o'reilly and purchase another set.they did the same when i cracked a plug in my c5zo6) and hopefully the car will be better. anything i could be missing??? possible bad pump in the tank??