Can anyone tell me what this is and where it came from. They were hot when I picked them up

was it near the tail pipe.  it looks like catalytic converter core material to me.  how is the power from the engine? 

Funny you should ask. Motor has about 260000ish miles feels very tired compared to my 88 with 158000 it had some ofthe vac lines plugged so I reconnected them and it ran stronger but started backfiring when the rpms dropped from 4k to 2k sounded like a 9mm going off under my seat startled the crap out of me and the car next to me. I just bought this hatch today and was driving home from Seattle going about 75-80mph my follow car told me it fell out the bottom but they couldn't say where from

Edited May 22, 20169 yr by Stihlman

From your cat, it can clog up he exhaust and run powerless untill unclogged

As far as I can see the only way it could exit the cat is to blow through my exhaust. I don't see any 1 inch holes in my cat or pipes. Does that mean that my muffler is literally shot full of holes internally?

''Does that mean that my muffler is literally shot full of holes internally?''

 

not necessarily. but not impossible. depending on the muffler and how it channels exhaust its likely that those bits manage to snake their way around and eventually exit the tailpipe. the converter itself isnt that dense to penetrate metal unless under a crazy amount of force. and the compressive forces required to do so wouldnt effectively be able to build up behind those bits to effectively shoot them through your exhaust system. its not impossible. but very unlikely. but would be kinda cool. asides from the destroying stuff and potentially hurting people

There is a pretty strong stream of air coming out of the tail pipe. It'd does not feel constricted and does not "chugga chugga" like it is backed up.

would be interesting to see if it actually did some damage to the muffler internals. . 

I would address the backfire issue first 

Looks like burned out catalytic core.  Normal working core is not black.  I once had the core dislodge in one of mine.  It moved around and mostly blocked the exhaust in the cat.  The car ran pathetically.  Weak.  Didn't want to accelerate.  Got it home.  Did a few tests, and discovered the cause mentioned above. 

 

Could have just failed due to age.  Or running rich, burning lots of oil, O2 sensor out of whack - but not so out as to trigger a trouble code. 

 

I would address the backfire issue first

it started backfiring when i unplugged the vacuum hoses and put them back on the air filter. What would cause that.

Edited May 24, 20169 yr by Stihlman

A Vacuum gauge will tell the health of your exhaust system. Those big pieces dont include the small peices you left all over the neighborhood.