[west_side_supra]

ok im confused, so my car was working great, boostin perfect a little lag here and there, drove it fine for about 3-4 weeks HARD!! and and and that stupid light came back on, checked it still a knock sensor. im not 100% shur on this but 86 octane gas didnt cause to many issues but then today i put 92octane in and now the damn light wont stay off it just keep going on and then ill turn it off and restart it and drive it and ill make it through 1st gear, then i goto 2nd and you can just feel it drag almost as it like what you guys said, leaky injector or maby a stuck injector or 2. if i make it through 2nd then ill goto 3rd and then it'll drag again kinda chugs along.

im also having an idle issue, i have read about this alot but everything is all diffrent or the conversation never was finished. be driving then come to a stop or put in the clutch or nutrael and then the RPM's just drop and then it chugs a little goes below 500rpm then will go back up. it will do it sometimes after running it then turn it off come back about 30min to an 1hr and start it and same thing drops down and goes back up. the car idles most of the time when its not doing it at 600-700rpm and COLD 900-1200RPM. dont know if this will make an easier answer to my issue.

should i just get a fuel upgrade kit? If so what should i get and where can i get it cheap? not ready to pay 1,175$ for a full upgrade, or the 870$ for the slight upgrade unless im shur this is my issue.