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Removing guts from cat conv.

  #1  
Old 06-06-2012, 09:39 PM
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Question Removing guts from cat conv.

I just bought a mint condion 87-SS with 60k original miles. She is all stock throughout and I like her that way. I did add 2 new insynerator mufflers from the cat back (new y-pipe and tails also). Going true dual proved to be more $$$, more complicated and it would have changed the original stock-ness of the car. The old muffs each had a small leak at the pipes and were WAY to quiet. I had it done professionally so as to make sure it was done right. They did a great job with the install and I was hoping for that low rumble of the typical insynerator mufflers. Much to my surprise the car was very quiet after the install-(too quiet). The mufflers did break in after a few days and now it does have a bit of a low rumble-BUT NOT ENOUGH.

Since it's a 25 y/o vehicle it only has to have a visual safety inspection of the car (cat included), Im in NY. I am considering gutting the cat to open up the flow of exhaust and creating a louder rumble thru the mufflers. Leaving it in place will satisfy the visual inspection of the car.

Any thoughts or experience on this decision. I'm doing this simply for sound value, not HP gain or MPG gain. This car is my weekend cruiser for local car shows and family Sunday morning drives (I'm not racing her). I see only 1 O2 sensor at the cat and apparently it will not be affected by gutting.

Thanks guys.....
 
  #2  
Old 06-07-2012, 07:04 PM
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Ditch it completely as a 87 there is no emissions inspection for that year any more.They can't fail you for it not being there.
I haven't had cats on my car I've owned it
 
  #3  
Old 06-07-2012, 07:15 PM
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If you are going to ditch I hear people are paying good money for them. There have been a lot of theft's around here of the kind that bolt on. Especially on trucks that people can crawl under...
 
  #4  
Old 06-07-2012, 07:55 PM
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i dont think that gutting your cat is really going to pump up the volume to where you want it. if this is something youre really interested in doing id pick one up a cat at the junk yard and cut it up the side with a cutoff wheel, gut it, replace yours with a piece of straight pipe, and wrap it with the outside of said gutted cat. i think whats making the car not really rumble is the motor itself, the manifolds, and the single small diameter exhaust that ys out to dual. if you wanted to make it louder. edelbrock sells a pair of emissions legal headers that should bolt to the factory exhaust. thatll probably make it slightly louder. personally i wouldnt even bother with either of those. id get a set of small diameter long tubes, no cats, run a madrel bent true dual exhaust with a pair of 40 series flowmasters. the headers are under 200 and the exhaust kit bent for the car itself is around 2XX. mufflers are like 50 bucks each. 500 or so bucks will give you the sound you want, better performance, and be easily returned to stock. all this can be found at jegs or summit.
 
  #5  
Old 06-07-2012, 09:32 PM
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Thanks for all the responses guys, it's nice to have fellow Monte enthusiasts give me quality advice. A good friend of mine works at a tire/full service shop. I'm gonna have him gut the cat and start from there. If it produces the desired sound than I'll stop there, if not than I'll consider some of the solutions posted here. I'll keep you posted.
 
  #6  
Old 06-07-2012, 11:39 PM
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Here in MO they can fail you for not haveing stock emissions equip on your vehicle if it was equip so. It fails inspection not emissions. If you want to gut it

1) Take off the exhaust from behind the cat.
2) Take a drill with a long bit one that is longer then the cat and drill all the way through it. Multiple holes if you wish.
3) Start the car and rev the engine. You will notice after it blows out its internals.
4) Reattach the exhaust and you are good.

You will "still" have a cat and will pass inspection. This is however illegal. The issue with removing the cat is not if it passes emissions it is if it passes inspection. In some places have dual exhaust by installing a cat back where a single exhaust used to be will fail the inspection.

For exhaust I would run long tube headers to a x pipe and glass packs instead of mufflers. This is if you dont care about inspections. I did this on my 70 dart and it is loud and has a nice grumble. The glass gets blown out after awhile and you are basically running straight pipes. But in 1970 there was no emissions equipment so as long as it does not pass a set desible level I can run whatever I want.
 

Last edited by Mr Grizzly Mint; 06-07-2012 at 11:46 PM.
  #7  
Old 06-08-2012, 08:34 PM
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He can't fail for no cat.It's no longer an inspectable item in NY.Now it's illegal for a shop to remove or modify the cat they just can't fail it.
 
  #8  
Old 06-08-2012, 10:50 PM
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I see diff laws in NY then. Thats good.
 
  #9  
Old 06-09-2012, 08:32 AM
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I'm not going to get into a pissin' match as to whose right or wrong, but keep in mind that Federal law trumps State and Local law. That means if your car came from the factory with a cat converter then (legally) you are obligated to retain it. A shop can face severe fines for altering or removing a cat converter, so although your friend may be willing to do so his boss may think differently.

I think TheMonteMan has offered the best solution if you want to increase the sound of your exhaust. The only thing I would do different is add a couple of high flow cats. There won't be any significant or noticable restriction and they will clean up your emissions at the tail pipe. If you want loud don't install an 'H' or 'X' pipe. They are good for a little more bottom end torque, but they also equalize the exhaust pulse and will cancel a portion of the sound.
 
  #10  
Old 06-09-2012, 09:00 AM
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Originally Posted by 03SSLE View Post
I'm not going to get into a pissin' match as to whose right or wrong, but keep in mind that Federal law trumps State and Local law.

I think TheMonteMan has offered the best solution if you want to increase the sound of your exhaust. The only thing I would do different is add a couple of high flow cats.
x2. Ohio's law is after a car is 25+ years old it doesn't have to go to an eCheck of ANY kind. However, you'll still never find a shop willing to lob the cat off for you.

You really only have 2 options, practice your welding skills and cut it off yourself, OR get high flow cats. I would go with the latter.
 

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