Need some expert help. My S2000 is jerky in 1st gear, has a rough idle, the Rpms are jumping from like 1000 to 2000 while in neutral and at idle and the Check Engine Light is constantly on. I always use 93+ Octane gas; however someone filled my gas tank up and I don't know what type of gas they used. I can almost bet it wasn't high octane. I have ran a bottle of fuel injector/carb cleaner through and ran about two tanks of 93+ octane from two different gas stations through as well. None of it has helped. I'm pulling codes today to see what I get and dropping it off at the dealership. Its still under warranty. Any ideas of what could be wrong? Could one tank of low octane gas make that much difference? And am I damaging my engine by continuing to run it in this condition? I don't want to hurt my baby.

 

This engine can run on low octane fuel. The ECU will just compensate for it. It won't run as strong but it won't throw a CEL either. Get the codes first before having a conniption. Since it's under warranty, let them deal with it.