Sparks from tailpipe

After some rather spirited, late-night interstate driving, I exited and stopped at the light at the top of the ramp. My friend who was following me pulled up next to me, and said he saw a “noticable amount” of sparks coming from where he thought was my exhaust as I stopped. I did notice a slight burning smell, but it went away pretty quickly. No smoke or loss of performance that I could notice (but I haven’t driven it hard since then.) Does anyone know what the heck this could be? I really don’t want to visit the man with the greasy hands.

No ideas?

Hey, I have been know to throw flames every now and again. I only have a resignator with my muffler and on chilly nights with hard driving small flames have shot out the back end. The resignator I have is custom made and is tapered inside so the exhaust actually speeds up as it passes threw, any unburned fuel may actually be ignighting. One of my buds has an 95’ MR2 running 15psi and I’ve seen him throw FLAMES, coolest thing.:cool: