while driving, my car dies when i push in the clutch. it started when i changed from 93 to 87 octane gas. have the sct x3 and changed the tune when i switched gas. idles kind of rough at startup but dies when the rpms slam down from a shift point or when stopping. any advice would be helpful. im 800 miles from home on vacation. im at my destination for a bout a week so i have a little time to work on it.