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 Mileage difference after a cat delete?

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200OZ
Cadet57
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PostSubject: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 10:26 am

Can one expect any noticeable change in fuel mileage after removing the cats? Time to free this thing up and maybe gain a few HPs and MPGs. Already has a pair of Thrush welded mufflers on it with stock tails. May decide to eliminate the resonators, too.
BTW...this is a '95 Caprice wagon.
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jayoldschool

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 10:53 am

When I had my muffler delete on my old 94 9C1, I didn't see any MPG increase. I drove 3hrs highway a day, btw. It was very loud (this was still with resonators), and the novelty wore off really quickly. I would never do it again.
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 12:11 pm

Talking about catalytic converters, not mufflers.
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Cadet57

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 12:15 pm

I did a cat delete on my '93. It may be placebo but I felt like the car had a bit more power and I actually saw a 2-3mpg increase. YMMV.

Also, Unless you do like a loud exhaust, I'd leave the resonator on with the thrush welded mufflers.
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200OZ
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200OZ


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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 12:52 pm

I put export (cat delete) pipes on my '94 Buick wagon, and saw no difference in mpg, it's just louder,
and it smells bad when sitting in traffic.... I love my export pipes.

Mike
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jayoldschool

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 2:56 pm

lol, I don't know what I was thinking...

The only thing you are going to gain from deleting working cats is more pollution.
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Mar 07, 2013 10:01 pm

I go to a cheap shop for that - it cost me 90.00 to replace the cat with labor! You can't even buy one at a parts store for that!

Amazing! All parts come in an unmarked box from Mexico! It must be part of the trade agreement! Wink
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeFri Mar 08, 2013 10:25 am

Well, it's going under the knife tomorrow. I'm gonna do it myself being an accomplished welder. I'll run with the resonators for now to see what it sounds like.
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GraypaHarwick

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeSun Apr 07, 2013 6:48 pm

A little off subject but I had my cat cut off (not by choice0 midnight in the boonies in KY)on my 01 Monte SS and got 1-3 MPG more. The check engine light now stays on.
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Apr 18, 2013 3:19 pm

Finally did it. Sounds mean and nasty when it's under a load. Really haven't had the time to compare mileage yet. Gimme a week.
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poppawoodie

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeMon May 06, 2013 7:18 pm

What are you guys doing about emissions
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeMon May 06, 2013 7:40 pm

poppawoodie wrote:
What are you guys doing about emissions

Poppa the answer is "Dont ask,dont tell". lol! !
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poppawoodie

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeMon May 06, 2013 8:06 pm

Flasheroo wrote:
poppawoodie wrote:
What are you guys doing about emissions

Poppa the answer is "Dont ask,dont tell". lol! !
I figured I guess I will have to wait 3 more years to consider mine a classic Wink but right now fighting mr sticker to tag me up. First go through I failed because of co and hc being to high, went back to mechanic and he said prob because of 180 on motor and timing is out due to slack in chain, he adjusted and my numbers did drop but now failing nox. Any legal sugg? I know plenty of illegal ones. My mech usually runs me through but his machine is down, so no bueno
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeMon May 06, 2013 11:20 pm

Switch to the normal 195 degree thermostat and that should do the trick.Others will chime in
here pretty quickly.
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poppawoodie

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeMon May 06, 2013 11:24 pm

Ive hijacked enough I will start a new feel free to chime in, its the only way monkey learns.
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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeTue May 07, 2013 10:59 am

I gained between 4-5 mpg on my first official roadtrip with them gone. Fortunatly, we don't have testing where I live si I'm not too worried about that.
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poppawoodie

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeTue May 07, 2013 10:35 pm

Glad to hear it, I will cut mine out in about 3 years when it becomes a legal classic. 3 to 4 is pretty damn good, why buy a foreign at that point. Id rather pay the extra for a little selfrespect while driving. Laughing
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phantom 309

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeWed May 08, 2013 1:34 am

3TONFUN wrote:
I gained between 4-5 mpg on my first official roadtrip with them gone. Fortunatly, we don't have testing where I live si I'm not too worried about that.

?????????????????? pfm.

nick
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Studebricker

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PostSubject: Re: Mileage difference after a cat delete?   Mileage difference after a cat delete? Icon_minitimeThu Sep 05, 2013 2:22 pm

poppawoodie wrote:
Glad to hear it, I will cut mine out in about 3 years when it becomes a legal classic. 3 to 4 is pretty damn good, why buy a foreign at that point. Id rather pay the extra for a little selfrespect while driving. Laughing
This is what I was just going to ask about -- so a 25 year old car doesn't have to pass emissions tests, that's the rule?  If so, I would rather wait and just do a whole exhaust redo all at once.
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