It's likely that you have a vacuum leak somewhere in the engine bay. I assume you're modded because you own a badass Mustang and you're on M6G, so take a look around the intake manifold, throttle body, air intake, etc. Also, reach out to your tuner with a datalog attached (if you're tuned).The title says it pretty much.
When idle cars RPMs going fluctuate somewhere between 600 to 800. They going up and down.
Is it normal.
Mustang, 2019, 20,000 miles.
Thanks.
No mods, but car did show light saying engine misfiring. Took car to the dealership, they cleared the light and said they did not find anything. And all is good.Nope, not normal. Usually indicative of a misfire or vacuum leak. Have you done any mods? Scanned for stored or pending codes?
Well, I would argue that just because the dealer chose not to find it doesn't mean it's not still there. Try another dealership perhaps. There should be a stored code for which cylinder (or a P0300 for random).No mods, but car did show light saying engine misfiring. Took car to the dealership, they cleared the light and said they did not find anything. And all is good.