car does not like hi-test gas

[Eagle85C4]

weird problem...anytime you give it the gas while moving the SES light would come on...code said bad knock sensor, so I replaced it. Now if I run 93 octane while crusing the light comes on with same code....but if I run 87 or 89 the light does not come on. I have replaced the O2 sensor as well. Any thoughts as to why it does not like 93?

[Shadowing1985v]

but maybe your ICM is going out

take it off and take it to autozone or a auto place store and have them test it

[drcorvette]

Weird!!!!
I seem to have the same problem recently.
Get a Knock sensor code. Changed my Knock Sensor ... same thing only occurs when I open it up. Changed my Electronic Spark Control ... same problem.
Maybe next gas fill up I will drop from 94 octane to maybe 87 to see if that corrects problem.
Keep me informed as to what you find and I will do the same.

Gary

[Shadowing1985v]

my car does the same thing too i think


guy's it can either be your idle air flow

or your iCM i think

i own a 85
i havn't fixed the problem cause im working on other stuff atm

but im looking into it
i get code 43 alot