was sitting in the garage, looking for a possibly bad coil and doing short revs to see if i felt hiccups (to like 4k RPM) and all of a sudden i hear a POP, super loud and weird, followed by a huge puff of white smoke, more like a cloud. so i go back to my exhaust and i find these pieces on the ground, some of them like 20ft away. Theyre still coming too, not sure WTF to think. presently not running the car, obviously, im afraid that i might suck w/e that is back in. There are a lot more pieces too, some of them looking more melted than these

[img=http://img143.imageshack.us/img143/9897/p7231012oc0.jpg]
[img=http://img143.imageshack.us/img143/9897/p7231012oc0.9535668832.jpg]

 

Yes, that looks to be pieces of cat material

 

hmmm, maybe ill be getting headers sooner than i thought

 

LOL, if you blew through your pre-cats I wonder how much more power you are making

 

lol, well MR. dyno says 240 so nothing special. is it safe to drive right now? would prefer not to have cat fragments in my cylinders

 

HA same think happened to me. i dont know if thats what came out of mine when it popped...but i had a loud pop and smoke when mine blew..i havent had any issues, but increase performance, because my car was lagging real bad in performance when i got it...my cat was clogged.

i'll be replacing my whole exhaust system real soon

 

Seems as though your cat ignited. Maybe from excess heat?

 

More then likely you blew your cat out (unless you don't have one) because your precats are behind you cat.. and that material would not have passed through your cat.

 

well i know it was my precat cause i have a test pipe = no main cat.

so is the consensus is that it is still safe to drive?

 

I would assume most of what was loose either blew out or is ready to. If there is still anything loose in your exhaust it would be smart to pull it off and dump it out.

I must say though, I've never heard or seen that happen before with stock, untouched precat/cat systems unless there are excessive miles or use on them.

 

well its got 9x,xxx miles with a LOT of racing included there so im not really surprised. in fact im happy as long as it doesnt get sucked back in

 

i wouldnt drive it....you could suck that material in to the cylinders and score the walls

 

I agree with Sooner on this one.

 

and thats why you should be sure to change the filter on your exhaust

 

yeah, im not sure WTF to do. buying new cats doesnt really seem to be an option, even discounted to daveB levels thats still like 1k for parts. cattman headers are 850 or some other alternative i dont know about. clearly i cant drive the car, i just remembered the problem the sentras had with sucking the cats back in and it seems like it would just be that much easier with pieces falling off.

 

Look in the 5th gen classifieds, I seem to recall seeing a few full exhaust systems in there.

 

so do you think i can get an exhaust shop to fab up a pipe to replace the cats? some seem to think they wont for legal reasons but i have no experience with that sort of thing and was hoping someone else did

 

A good muffler shop should be able to help you out.

 

you could take em off and try to knock out the rest of the cat material, otherwise i doubt an exhaust shop would be able to make something bypass them or w/e. Ever try welding cast iron? Its next to impossible.

 

well ill be calling exhaust shops early in the morning, hopefully they can help me out. the last thing i want here is to replace them with stock precats...

 

If you're up to taking them off the car they should be easy to hollow out. That material is very brittle and comes out easily. Just be sure to use a mask so you don't breathe any of it in.

Unless you know the shop they probably won't remove cats. There's a big fine if they get cought and one for you too. I'm not saying don't do it, just be careful.

 

definitely don't drive it or even start it to drive to a shop.
Even if you hollow your precats you will never pass emissions and it would smell pretty nasty if daily driven since you don't even have a main cat. Same story with cattman headers. Some ppl drive like that, including myself on the previous car but would not do that again.
Your decision!