Ok mods:
k&n fipk
Skunk2 megapower duals
Invidia tp
Berk headers (ceramic coated)
2002 ap1 (incase)

Issue:
i was coming from the modified meet tonight and ran it up pretty hard, not gonna admit to my speeding tho. The moment i hit the brakes, sparks started tumbling out of the exhaust. Ive had it happen before on several occassions, but the car sounds like its running fine etc, and its always on deceleration. And it has to be veryyyyy hot, like to 8.8k thru 3 or 4 gears and then decel and i see sparks. I can run all the way thru sixth as hard as possible and no sparks... till i decelrate... other forums seem to say its the exhaust fiberglass melting, or possibly carbon build up breaking loose?

Really hoping for more unput here, thanks.

 

probably caused from having multiple headers...s2ks should only have 1.

 

I would say it is superheated bits of carbon getting knocked loose and blow out.

 

Do you have a test pipe ?

Are you talking sparks or flames ?, do you hear any back fire type noise when it happens ?, or just see the sparks without accompanying noise?

It could be unburnt fuel blowing out the tailpipe, perhaps carbon, usually more visible on cars with test pipes.

 

@redcelica congrats, yet another useless comment

I have a test pipe, completely open exhaust... there are no flames or popping sounds, just the sparks flying out. I was assuming it was either the packing or carbon... but its only when i slow down, thats what makes me feel wierd about it. It still runs fine, pulls hard (cept i need a new clutch soon) and it doesnt do it unless its reallyyyyy hard driven then slow down fast.

 

My guess would be the packing inside your skunk2 duals (honeycomb looking thing)are coming apart. Is your test pipe resonated or non-resonated?

 

If its flames, its afterburn. Its ok. Mine does like 4 foot flames at the same time you say yours happens, run really hard and only on decel.

Its unburned fuel being burned by the super hot exhaust.

 

non-resonated test pipe... my entire exhaust only has 2 spots that arent a straight pipe... there is a resonator about mid ways between the cat and the rear axle, and the two mufflers themselves. other than that, there is nothing else it could be. I think my exhaust is falling apart, ive had my mechanic tell me on the phone (while laughing) that he has melted and shot so much crap out his. Its just throwing me off because.... why is it only when im slowing down that crap shoots out? why not while im running it up hotter and hotter?

 

Because when you have the throttle plate open there is air in there also, when you let off for that split second the injectors are still on and it goes full rich and only fuel is in the exhaust.

 

3rd gear @ 8.8k rpm is about 75mph... Not saying you were speeding though lol

As for the sparks, i dont believe the particles could possibly come from the engine; probably from exhaust manifold onwards