Keep going thru cats

[1968cyclone]

2003 GT.
I have long tube BBK headers and MAC catbacks. When I got the car, it had an O/R H-pipe which I replaced with a BBK H-pipe with cats.

After a few months, the cats started to rattle from the inside - so I had them both replaced with new high flow cats. Well, after a few more months, those cats started to rattle.

Anyone have any idea why I keep going thru them? Any thoughts would be appreciated.

I'm not getting any codes from the front O2 sensors. (or anywhere else). There are MIL eliminators on the rear sensors, so I don't know if there would be a code there.

 

[DTNODYA]

Do you have emissions testing where you live? If not, get an H or X, with no cats!

Otherwise, I don't know why they keep going bad. I also didn't know you needed MIL eliminators if you had cats ....

 

[1968cyclone]

yup - we have emissions testing - which is why I put in the cats.

I had the MIL eliminators - so I just left them in there. I wasn't sure if the non-stock cats would throw a code.

 

[Kilgore Trout]

They probably keep going bad because you keep flooring it all the time, not that there is anything wrong with that...

 

[Skud]

If you car is running very rich it will make the cats run way too hot and the material inside will become brittle, break off and rattle around..

I'd maybe get tuned..

Riley

 

[SaleenGT2001]

do they actually look under your car. i know mine is so low they cant see anything under it. heres an idea. take the mid pipe off, beat the internals out of the cats and then leave your mils plugged in. it will look like you have cats but there wont be anything there!!!

 

[Mike97gt]

Mustang midpipes are so easy to swap why not go catless 364 days a year and swap in your stocker for when you go to test.

 

[1968cyclone]

> Keep flooring it all the time
Uh, well, guilty as charged.

> Running too rich , need a tune
That was my thought

> Swap out with O/R H pipe and run cats 364 days a year
Yup - that's the way I'll prob go. Only 8 bolts.

> Do they look under your car
Yes. My last inspection they put it on the lift. They saw the MIL eliminators. I'm assuming they passe it becuase technically it passed. It threw no codes - and visually it had Cats. That's all they needed to do. I think they put it on the lift to see what it had. Problem i have - I do all the work on my cars myself - so i really do not have a friendly place to bring my car too. (they did overlook the tinted windows - gotta like that).


And I got kinda bored the last few days at work. Surfed the car.com ads - and bought a '98 GT convertable today. I guess I gotta tell my wife soon. I told her I was going out to buy golf clubs - oh, bought those too - just a set of irons - - - - But they were on sale

 

[1968cyclone]

had that backwards - I meant run cat-less 364 days a year.

 

[Pennywise2]

Yep,get a catless Bassani X pipe.

 

[Skud]

I wish I could find a set of heat shields that go over the cats. Then I could just mig them where the cats would normally be and nobody would be the wiser.. I have an O/R Magnaflow X BTW..

Or just make a "shell" that looks like a cat out of sheet metal and mig it to the pipe...

EDIT: Now my brains a 'goin.. Is anyone here good with AutoCAD? If someone could draft a "shell" that would fit around a 3" exhaust pipe and looked like a cat.. Then I'm sure AutoCAD could print out the blueprints for the shapes that need to be cut out of sheet metal.

Then just buy some sheet metal, trace the shapes, cut them out, weld it all together and then tack weld it to your midpipe (or even hose clamps)..

Hmmmmmmm......


Riley

 

[EPIK]

I like the high rpm power that I got when I recently installed my Bassani off road
X pipe, but I wish it didnt sound so raspy though. I wanted to go with a catted x or h pipe but I got mine 4 almost free from a freind who only used it for a couple of weeks so I didnt see any reason spending all the money on a new catted 1. I plan on adding cats soon because I need 2 smog mine also, and the raspiness is 2 annoying. Dont get me wrong it still sounds good, but its too loud. Im hoping the cats will quiet it down a little bit while also helping me pass emissions . My GT didnt sound raspy at all, but it had a Bassani catted x, shorty headers, and a flowmaster catback. It did have a ton of interior drone though.Thats why I thought I would try Magnaflow this time around. So back to the cats, What high flow cats should I use, and where can I get them at a decent price. Sorry 4 hijacking your thread.