i was driving my car on the freeway the other day and top speed the car. then i drove to a gas station to get gas and it was the first i ever use 89 gas with the b16 in the car. i was driving okay until my car starting feeling like its pull back power. is this due to the 89 gas??? should i put 91 in with it?? i have more than half a tank left in the car. i dont want to drive it and blow it up if anything is wrong. need help asap!!!!1