Well I thought that inside my filler cover, it says use premium unleaded only.
I use 92 octane here in los angeles, but there is a place that sells 102 octane. I'd be afriad to use that because I dont know if my fuel system can handle it.
Perhaps 97 is the issue, do you have access to lower octane gas?
Perhaps you can dilute it down a bit with some 87 octane and see if the condition improves?
I'd Wait for a pro to answer this, I'm just guessing at things but thought it might give you some insight.
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