ok, i just got a custom 3" catback with the ebay downpipe and a resonated cat delete. i have white/grayish residue inside the exhaust tip instead of the usual black. could it be the custom piping? i've also been running 100 and 110 octance for three days straight the very day i got the exhaust on there. any help?

 

The white is caused by the lead in the race gas. Nothing to worry about.