my 95 maxima. just bought it at 140,000 miles has encountered a few problems. the guy before me ran 93 octane since he bought it. i was not aware of this and ran 2 tanks of 87 recently. check engine light appeared soon after. codes came back as knock sensor, engine temperature sensor, and o2 sensor. i'm thinking the engine head temp sensor is mostly at fault since it wont start now on the first try unless i give it some gas. the tach was fluctuating before, but it would start on the first try. I'm gonna replace the eng. temp. sensor and the O2 but am curious is i am on the right track here. anything else i should look at?

think just going back to 93 octane will solve the problem?

 

knock sensors always go bad on maximas, have to change that too