On-throttle under-load "Dieseling" type noise... Header gaskets?
 

Last couple weeks I've been hearing a new noise with my exhaust, it only happens under load when accelerating usually at lower RPM's. Its loudest from the passenger side footwell, and sounds like an old pushrod Subaru (or an old VW bug if you are less familiar with Subaru's :P ).

There is no noticeable change in performance and no codes are being thrown.

I've had this exhaust setup for a year, and this is a new sound:

Revworks Header
Nameless catted but resonatorless overpipe/catpipe combo pipe
Stock midpipe
Legsport muffler
OFT
TRD intake

Couple videos:

[ame]http://www.youtube.com/watch?v=nUneTAfBr_I[/ame]

Sorry for the black screen, but that was in the dark. You can hear it when I hammer the gas a bit, but its much louder in person than in the vid.

[ame]http://www.youtube.com/watch?v=0Zv2V4khB8I[/ame]

Thats starting up the car and idling (its not the ticking noise at the end)

I'm going to pop off the skidpan Friday and take a look see, and I ordered some new gaskets for the header just in case that is the problem, but I'm hoping someone has had this exact noise so I can be sure before then, thats all... Thanks!

this comes to mind. your engine is a '13 as well.

http://www.ft86club.com/forums/showthread.php?t=81496

Thats a "clack" noise, mine isn't like that.

look at your long term fuel trims if you have header leaks they will probably be high positive at lower rpm

look for black stains or moisture at joints on a cold start

Found the problem...

http://i.imgur.com/hf0BOOf.jpg

Yup, that entire seem has cracked/separated on the header :(

Going to have to remove them and have them fixed.

I'm glad I was wrong!