broken cat question
 

My front cat on the left side broke inside and was making a rattling sound. It stopped and I did not think about it anymore. Know it is letting just enough air though that in normal driving there seems to no problem. If I hit the gas even a little hard I here a weird sound that I can not discribe from the that side of the engine. I thinking that has to do with the blocked cat. My question is will this hurt the engine. I was thinking of getting an of road h-pipe, but I have to convince the wife that it is a needed fix.

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Steve Stumbaugh

89 LX 5.0 5sp.
Removed air silencer
Motorcraft 8mm wires
Autolite platinum plugs

The catalytic element is a rock-hard piece of who-knows-what with a bunch of little tiny holes in it. If pieces of the element become dislodged and the holes dont flow air anymore, depending on how big of a piece, I would think it would give too much backpressure. I cleaned out my cats awhile ago and now I am hearing this sound from like my muffler area. It sounds like things are rolling around in the exhaust when I brake. I'm wondering if I missed some element when I cleaned it, or it could be totally unrelated. Does yours sound like that? An offroad h-pipe would be a good addition anyway http://www.mustangworks.com/msgboard/smile.gif

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Blueneonman - '95 5.0L Mustang GT Convertible | K&N Custom Cold Air Intake | FMS 9mm Wires | Hollow Cats | Flowmaster 2 Chambers | BBK Subframes | 6-pt Rollcage | 14deg Timing | King Cobra Clutch | FMS Adjustable Clutch Cable | Coolest Neon Lighting on a Mustang EVER!

Homepage: http://www16.brinkster.com/blueneonman/

Best time: 14.578 @96.20mph

When the catalyst in my catalytic converter broke up it was blocking my exhaust, I pulled the whole exhaust system off and shook four pieces of a half melted honeycomb out of my muffler. When I was climbing a hill I could literally feel when the pieces dislodged and went into the muffler. I'd say it sounds like you've got a legitimate case for removing a stock convertor. Do you have smog testing there?

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GT-40 heads (ported, polished, + milled), B303 cam, 1.7rr's, JE pistons, Offy intake, Carter AFB 625cfm carb, Flowtech 1 5/8" shortys, Flowtech X-pipe, MAC Flowpath exhaust, MAC pulleys, 373's, subframes, Eibachs+Tokicos, B+M ripper, FMS Clutch, Zoom Quadrant+cable, 17" CSA Ultra rims, 235/45ZR17 Yokohama AVS S4's, MSD 6A ignition+coil, FMS 9mm wires, Carbed, Naturally Aspirated, and Nasty!

I heard it in both right side cats. Like I said it just stopped until a few weeks ago. With having to much back pressure, will that blow any seals or damage anything?

It'll make that bank run rich, foul your plugs, drop your fuel economy, in short, I'd do something about it immediately.