Happend to my UR metallic HFC on 350z. Never run HFC after that.

 

What in the world made you look in there?? Lol

 

because i literally looked everywhere else and there was nothing left to check and was about to take the turbo out. Yeah i cant recommend AMS HFC anymore. they literally stink. I may have an upgrade to TP but now i gotta dish out money for a retune

 

I bet all that packing material made the exhaust real quiet.

What kind of fuel are you running? Have you changed the deccel fuel tables? I know that fresh air through a cat (like when you downshift and fuel shuts off) can cause unexpected heating of the catalyst materials..

 

Ew.
I have the Mil.Spec HFC. Hope mine don't do this. Now you make me worry about stuff and stuff, lol..

 

Just octane 93

 

I've heard of this happening but first time seeing it. Damn that sucks. Sucks on the warranty as well, but that particular company left for GT-R land a long time ago.

If they made the X one like the IX/VIII one you should be fine. I've had mine for over 6 years now on my VIII that I track.