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3/31/07 8:14pm - Original Message: 'Catalytic Converter Removal??'
Blue-79
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Ashburn, VA - USA

Vette(s):
1979 L-48 Coupe, 4-speed, Blue/Blue, in family 20 years

Joined: 3/16/2007
Posts: 48
Did you hear about the lawyer who discovered that a client had inadvertantly given him TWO $100 bills to setlle a $100 debt??
 
The attorney struggled with the moral question; "Should I tell my partner??"
 
My moral question relates to the possible removal of the cat converter from my '79.
 
Now first let me say that I am very GREEN. I recycle everything. But I question if a converter that is nearly 30 years old does anything. And I know they run very hot, and if clogged cause performance problems and may add to pollution.
 
My question to the jury then, what effect would removing the converter have?
 
I am thinking of going to side pipes.
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3/31/07 8:20pm - Reply: 'Catalytic Converter Removal??'
Gunslinger
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Frederick, MD - USA

Vette(s):
1969 convertible L71 427/435 4-speed black interior

Joined: 9/8/2003
Posts: 3398
Remove the converter if your state doesn't perform emissions tests anymore after the car reaches a certain age...usually 25 years, but not all states allow it.

If your converter is partially or fully clogged, it will definitely run better. Even if it is operating OK, remove it and install a true dual exhaust system (or sidepipes) and the lessened back pressure will free up some horsepower and the car will run better...maybe cooler. No converter also will lessen the heat under the floorboards.

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4/1/07 8:22am - Reply: 'Catalytic Converter Removal??'
lukesvette Lifetime Member
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HOWELL, NJ - USA

Vette(s):
1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.

Joined: 5/18/2004
Posts: 6806
Emissions go out the window when the converter is removed. A tough decision for a GREEN preson.
 
Then again, as Gunslinger mentioned, it's like giving your motor a get out of jail free card...
 
However, there are more expensive routes, for example, upgrading to a high performance converter....Confused


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4/1/07 8:36am - Reply: 'Catalytic Converter Removal??'
tuxblacray Lifetime Member
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Greensburg, IN - USA

Vette(s):
Previous: 1984 Silver / Charcoal Coupe, 1988 Maroon Coupe / 1989 Artic White / Mod. Red Int. Coupe, Present:1976 Stingray Black / Black, Auto, 350 slightly modified (355 hp) Luxor Wires Redline Tires. / 2001 Speedway White Vert, Torch Red Int, LS1, Auto.

Joined: 9/24/2003
Posts: 5174
Headers ... Converter ... whatz that ??? Let me think... ya reckon the Harley guyz have converters on their bikes? NOT.... Take it off & rest your green mind. Let that car breath.

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4/1/07 3:49pm - Reply: 'Catalytic Converter Removal??'
Blue-79
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Ashburn, VA - USA

Vette(s):
1979 L-48 Coupe, 4-speed, Blue/Blue, in family 20 years

Joined: 3/16/2007
Posts: 48
OK, Thanks to all.
 
VA does notrequire that I pass the emissions tests any longer. I only have to go through the safety inspection at this point.
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4/5/07 8:44am - Reply: 'Catalytic Converter Removal??'
maintenance4
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Tecumseh, MI - USA

Vette(s):
1980 all org. with 18000 act. miles dk claret with matching interior..Eagle alloys ..loaded..excellent cond.

Joined: 9/14/2003
Posts: 221
Year's ago, they use to sell a (test pipe) which replaced the converter. Wish I could get my hands on one now. Put one on my first 80 years ago, what a difference it made...

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4/5/07 10:29am - Reply: 'Catalytic Converter Removal??'
crossfire1982
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Cramerton, NC - USA

Vette(s):
black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion

Joined: 8/22/2006
Posts: 1094
Jerry, if you ever find a source for those test pipes for our cars, please post the supplier.  I can find them all over the net for the ricers, but not for any domestic cars.

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4/5/07 11:40am - Reply: 'Catalytic Converter Removal??'
dwright Gold Member
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Victor, NY - USA

Vette(s):
2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe

Joined: 7/12/2004
Posts: 6757
[QUOTE=maintenance4]Year's ago, they use to sell a (test pipe) which replaced the converter. Wish I could get my hands on one now. Put one on my first 80 years ago, what a difference it made...[/QUOTE]
 
You will sometimes see these on e-bay.


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4/5/07 1:00pm - Reply: 'Catalytic Converter Removal??'
PSU 98
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Shenandoah, PA - USA

Vette(s):
1982 Chevrolet Corvette

Joined: 10/18/2006
Posts: 328
If you really wanted to run a straight pipe on your 'Vette I'm sure you could have the flanges cut off the stock coverter and TIG welded onto a section of stainless pipe.

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4/5/07 4:10pm - Reply: 'Catalytic Converter Removal??'
767REP Lifetime Member
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Joined: 3/31/2007
Posts: 293
I talked to my local muffler shop and (1977 l48 stock) he told me that any car that originally had a cat cannot be modified by a shop due to a 2500.00 federal fine. He ajso told me that factory cats were 48% resrictive and the new cats are 95%.He told me the sound and performance with new cats would be like no cats at all.Any ideas?

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4/5/07 4:13pm - Reply: 'Catalytic Converter Removal??'
mbarney
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Davie, FL - USA

Vette(s):
1980 l48

Joined: 2/29/2004
Posts: 173
Do it yourself with this http://cgi.ebay.com/ebaymotors/CHEVROLET-CAMARO-Z28-CORVETTE-TEST-PIPE_W0QQitemZ330105437600QQcategoryZ33633QQcmdZViewItem

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4/5/07 4:19pm - Reply: 'Catalytic Converter Removal??'
Gunslinger
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Frederick, MD - USA

Vette(s):
1969 convertible L71 427/435 4-speed black interior

Joined: 9/8/2003
Posts: 3398
Modern, performance cats are very high flow. Look at Summit Racing or Jeg's...they carry high performance cats and they're not really expensive. Maybe some modifications to your exhaust since they're not application specific, but that's about all.

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Poet...Mystic...Soldier of Fortune. As always...self-absorbed, adversarial, c o c k y and in general a malcontent.

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4/6/07 9:47am - Reply: 'Catalytic Converter Removal??'
Greg78SA
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Saginaw, MI - USA

Vette(s):
1978 Silver Anniversary... Almost all original/correct L48 auto,59k miles, oyster.

Joined: 9/22/2006
Posts: 146
There's a hefty penalty (Fine and possible jail time) from the feds for  using a test pipe.  However, Nextag sells em as "cat con replacement units"  with  the caveat that they are not street legal.  My corvette shop guy says there is not much to be gained.  I poked around some more and got numbers between 3 and 5 hp as a gain.  AND the lack of a converter causes issues such as hesitation, etc.
 
 IMHO...Not worth it!
 
Greg


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4/6/07 2:10pm - Reply: 'Catalytic Converter Removal??'
Greg78SA
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Saginaw, MI - USA

Vette(s):
1978 Silver Anniversary... Almost all original/correct L48 auto,59k miles, oyster.

Joined: 9/22/2006
Posts: 146
Oh, and the corvette shop guy said he'd never seen a catalytic converter wear out...he's 52 yrs old.Smile

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4/7/07 12:26am - Reply: 'Catalytic Converter Removal??'
Gale Banks 80 Lifetime Member
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Vette(s):
1980 with a Banks Twin Turbo 1969 Convert Big Block 1996 Grand Sport Convert

Joined: 9/8/2005
Posts: 241
  I put a Test Pipe on My 80' way back when it was nearly New. Couldn't stand the Sound of it it makes for a Raspy Sound threw the Stock Mufflers. It might of Sounded a Bit Faster but that was all I gained so I put the Cat back on after a Week. Keep in Mind that a Corvette Comes from the Factory with 505 HP threw Cats these Days. The best is a True Dual Exhaust with Twin Cats Like every Vette has come with for the last 20 Years but You Cannot Buy it You will have to make it because of Legalitys. Keep in Mind Cats are just Like any other Exhaust Product Bigger is better. Richard....

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4/7/07 7:30am - Reply: 'Catalytic Converter Removal??'
maintenance4
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Tecumseh, MI - USA

Vette(s):
1980 all org. with 18000 act. miles dk claret with matching interior..Eagle alloys ..loaded..excellent cond.

Joined: 9/14/2003
Posts: 221
The main reason I would like to eliminate the cat. is to cut down on the interior heat that comes from the converter. Even though I do have a/c, I like the wind blowing through what hair I have left. Thank's for the imput guys. Will consider my options on this one. Maybe I will go with dual exhaust...

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4/7/07 4:59pm - Reply: 'Catalytic Converter Removal??'
Sarge81 Lifetime Member
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WEST SENECA, NY - USA

Vette(s):
1981 Blue Ice Met. w/pearl ghost flames TKO500 5speed. LS1 Swap 3.45 Dana 44.

Joined: 12/3/2001
Posts: 2376
[QUOTE=maintenance4]Year's ago, they use to sell a (test pipe) which replaced the converter. Wish I could get my hands on one now. Put one on my first 80 years ago, what a difference it made...[/QUOTE]
 
PM sent.


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4/7/07 5:56pm - Reply: 'Catalytic Converter Removal??'
eddie20875 Lifetime Member
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Lanoka Harbor, NJ - USA

Vette(s):
1975 metallic blue coupe with t-tops,L48, t/t steering, black leather interior. 1990 L98, white/red leather interior, auto,a/c

Joined: 12/21/2006
Posts: 828
[QUOTE=Greg78SA]Oh, and the corvette shop guy said he'd never seen a catalytic converter wear out...he's 52 yrs old.Smile[/QUOTE]

i understand corvettes are top notch cars but for him to state he never seen one go bad leaves me wondering. i am 52 and i have seen cats go bad not only on one of my cars but on other peoples cars as well. granted my car wasn't a corvette, it was a cadillac. after a lot of aggravation the dealer found it was the cat was bad. of course it wound up costing 600.00 thru the dealer to replace it once it was done the problem cleared up.

as i have headers on my vette there are no cats on my car and it doesn't sound bad. it has to me a great sound at idle like the power is waiting to be unleashed and cruising sounds great too.
eddie208752007-04-07 15:58:49

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4/8/07 12:37pm - Reply: 'Catalytic Converter Removal??'
Autom8r
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Old Hickory, TN - USA

Vette(s):
1978 L-82 Silver Anniversary hotrod. /////////////

Joined: 5/26/2003
Posts: 599
I have an '82 Chev pickup with a 305 4-bbl. It always got 13.5 MPG. I pulled the cat off and the mileage went up to 16.5 MPG. Can't say much for the performance, cause there never was any in the first place. It is registered in a county w/o smog tests....

My 'Vette has full length headers and a 2-1/2" true dual exhaust blowing out thru straight-through Walker welded Dyno-Max mufflers and the ZZ-4 sounds and runs perfect, with 20 MPG hwy.

I never have been a big fan of cats, steel and platinum or 4-legged.....

Dave

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4/17/07 3:25pm - Reply: 'Catalytic Converter Removal??'
sfindlan
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Badin Lake, NC - USA

Vette(s):
1979 Red L-48 Corvette with Doeskin interior, 3-speed automatic, 3.55 rear; 1986 L-98 Coupe, 4+3 Manual - Satin Black and Purple (SCCA TT/Hillclimb Car); 1993 White LT-1 Coupe, Black Interior, 6-speed

Joined: 4/21/2004
Posts: 101

I am 51 and can say that I have seen cats "wear" out by the internals coming loose, causing blockage. I have also found the internal mesh (on the monolithic ceramic types) clogged.  My solution is to use a large hammer drill to "clean" out the blockage and put the cat back in place.  If you don't like the sound - get new mufflers - many great sounding cars were built in the 60s/70s without cats.  I have always seen an increase in mileage and performance - even if it was only 1 or 2 mpg.



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C3: 1979 Corvette Coupe, Auto, L-48, Red/Doeskin (my wife's fave);
C4s: 1986 C4 coupe (SCCA road race car), satin black, 4+3, Z51 package, L-98;  & 1993 C4 coupe, white, 6-speed, LT-1.
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