Catalytic Converter Rattle - Not the Shields

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rjfoy

New Member

Dec 2, 2003

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May 4, 2004

#1

• May 4, 2004

• #1

My cats sound like a box of rocks. It isn't (unfortunatley) the heat shields, it's the material inside. When I bought the car it had off road pipes, but I had new cats installed to pass inspection. They lasted for about 6 months until the material inside broke up. The company covered it under warranty. Now it's doing it again and they won't cover it again because they said it was a fuel issue. So a couple of questions for you 5.0ers.....has anyone ever tried breaking up the material inside? Not exactly legal but it would work to pass inspection, kinda like stealth off-road pipes. Anyone have any idea what might cause this? Thanks, RJF

 

88stangmangt

Active Member

Nov 25, 2003

2,332

1

48

Stafford,VA

May 4, 2004

#2

• May 4, 2004

• #2

poor design, running rich do you have the timing advanced? you can bash out the inside's with a pry bar,coat hanger just about anything you can snake down there and pound the crap outta it. and use some thing to pull the fins out how about a brand? so we can stay away from them?

 

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89lxsport50

10 Year Member

Feb 25, 2003

550

5

39

Franklin Tennessee

May 4, 2004

#3

• May 4, 2004

• #3

My MAC high flow cats did the same thing after a couple of years. I got pissed about it and stomped it on the interstate one day. It made a small cloud of smoke and never rattled again. That was a year ago.

 

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rjfoy

New Member

Dec 2, 2003

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May 4, 2004

#4

• May 4, 2004

• #4

It's stock tuning, but I'm not sure about the injectors, fuel pump, etc.

The brand is AirTek as sold as CATCO.

Thanks for the comments. I'm gonna clean them out this weekend.

 

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Daver

New Member

Apr 24, 2004

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May 4, 2004

#5

• May 4, 2004

• #5

Hmm.. Seems most any catalytic converter's do that now days, on the second set on my Dakota RT now and they are rattling, too bad it isn't under warranty anymore...

 

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88mustangGT

New Member

Apr 6, 2003

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May 4, 2004

#6

• May 4, 2004

• #6

mine just started doing it today as well, sounds like a rock or somthing is stuck in there. is there anything i can do or should i just wait for it to pass?

 

88stangmangt

Active Member

Nov 25, 2003

2,332

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48

Stafford,VA

May 4, 2004

#7

• May 4, 2004

• #7

88mustangGT said:

mine just started doing it today as well, sounds like a rock or somthing is stuck in there. is there anything i can do or should i just wait for it to pass?

Click to expand...

hahahah my brother more than likely it wont pass since your honey comb fins have broken loose you could try you might get lucky.

 

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88mustangGT

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Apr 6, 2003

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May 4, 2004

#8

• May 4, 2004

• #8

so does this mean these cats are usless now when emissions time comes around?

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

May 4, 2004

#9

• May 4, 2004

• #9

Certainly if you pull the internals out, they'll be useless in terms of helping you pass the sniffer. If a visual is all you're after, then trying to break up the ceramic matrix inside and remove it may work. Just be prepared - once you break it up inside, if you can't get the stuff out, you'll really screw up the flow characteristics of them. If you don't get the stuff out, they can create a heckuva pressure drop that will hurt flow.

 

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rjfoy

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Dec 2, 2003

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May 5, 2004

#10

• May 5, 2004

• #10

Michael, Don't you think that if you can break the pieces small enough, and I don't know how hard that is - never tried it before - that the pressure will just blow them out the cats? Bob

 

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5literPwr

Founding Member

Jul 17, 2002

122

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May 5, 2004

#11

• May 5, 2004

• #11

Heh, Catco ah? I had the same prob. Sounded EXACTLY like a box of rocks for me too. Catco is junk. I say this because i had the same exact prob and doing some searching, I discovered that i wasnt the only one who had this complaint. Anyways, what made it so much worst is that I got Catco cat'd h-pipe from Summit, and they told me to return it to them (summit) so they can inspect them to determine if it was damaged due to design or my neglect. Anyways, summit determined in favor of the junk design of Catco, and so it was a total waste of money plus the costs to have them shipped back to summit. Had this piece of crap h-pipe for no more than two months, and my car was determined from an exclusive and well known east coast shop to not be my cars fault, (had my state of tune inspected before i sent them back) but guess summit knew better. Anyhow, sorry for summit to decide against my favor, as they lost me as a customer, not to mention several 5.0 buds of mine. I gave lots of business to another parts supplier after that incident, which would've been summit if they made the honest decision. Anyways. Catco is junk, and summit defended them in my case. Screw the both of them - Summit, ya lost lots of business you twits!! Stay away from Catco for sure!!

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

May 5, 2004

#12

• May 5, 2004

• #12

rjfoy - the pressure may push them back - but to where? Further down the exhaust system where most of us have a muffler that will act like a big filter to catch them. You can clog up the cat, or you can clog up the muffler. Same effect. If you want certainty, you've got to have the cat off, and break them up/get them out of the system.

 

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88mustangGT

New Member

Apr 6, 2003

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May 5, 2004

#13

• May 5, 2004

• #13

then after most of it is out throw it back up on your car but dont hook up your cat back and go for a ride to get the rest out? would that work

also my rocks in my cats seamed to stop by today it lasted about 2 days. also there was a bunch of white cotteny stuff on my garage floor at the end of my mufflers. would you say my cats are dog food?

 

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mattfleming

New Member

Mar 22, 2004

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May 5, 2004

#14

• May 5, 2004

• #14

If you do go in to "gut" them out, put a piece of pipe THROUGH the cat the same size as your other piping.. the wider area will kill your exhaust velocity coming off your headers. a pipe in there the same size as yoru exhaust will help keep your velocity in the ballpark and keep you from losing torque and horsepower.

 

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rjfoy

New Member

Dec 2, 2003

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May 5, 2004

#15

• May 5, 2004

• #15

I had planned to disconnect from the Cats back (manifold side is welded), break it up and then blow it out before I reconnected the pipes to the mufflers. But Matt makes a good point, that big empty chamber has got to effect the performance. Damn, this is turning into a $450 pain in the #$%!

Just trying to put a pipe through the cat without tacking it somehow sounds like another rattle waiting to happen. Any adivce on how to have the pipe fit in there solid?

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

May 5, 2004

#16

• May 5, 2004

• #16

You're probably gonna be better off in the long run if you have a muffler shop cut them out (ok - unbolt the back), break them up and shake it all out, and then weld them back in. That assumes 1) you don't have sniffer to pass in the future, or 2) you can find a muffler shop that will do it (most will stay far away from that sort of 'mod'). If you've got to pass the sniffer, in the long run you're gonna spend less money and have fewer headaches if you bite the bullet and go ahead and install quality cats. Contrary to popular myth, properly sized quality cats have little negative impact on flow.

 

djk8705

New Member

Sep 30, 2003

154

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Fairfax, Va

May 5, 2004

#17

• May 5, 2004

• #17

whats it sound like thru out the rpm range? I've got a horrible rattle that sounds like a heat sheild but i cant find it at all. Its only at around 1500-2000 rpms... I figured it could be a broken piece of the Cat? Does it sound like yours did/does? Thanks

-Dan

 

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rjfoy

New Member

Dec 2, 2003

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May 6, 2004

#18

• May 6, 2004

• #18

You're right it would be darn hard to find a shop in VA to do this - big time fine, and I just don't have the extra $$ right now to install new ones.

DJK: I don't notice mine unless I'm stopped, but it does do it through the idle range from idle to about 3K. No doubt it's doing it all the time, but my car is so loud when driving I think it mask the cat rattle.

 

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rjfoy

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Dec 2, 2003

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Jul 24, 2004

#19

• Jul 24, 2004

• #19

I ended up taking them off, using a pipe to break up the ceramic and bolting them back on. Pain in the butt to maneuver if you can't your car pretty high off the ground to work on it, but it wasn't that hard to break the stuff out - sounds a little tinny, but not as bad as that damn rattle.

 

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ratrapp

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Apr 24, 2004

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buena vista,va

Jul 24, 2004

#20

• Jul 24, 2004

• #20

i don't know about catco being crap but i've had one of there high flow cats on my 88 jeep p/u for 4&1/2 years now and it's fine.i don't reccommend a merit pipe though.i installed one of there 2 cat h pipes today on my car and it's fit is awful.it wouldn't fit in the tranny hanger right(had to heat and bend the exhaust tangs)and it was shorter than stock so now i have to heat and slide my mufflers and tailpipes back farther so they don't rub my trailing arms.