Here's a picture of a cat that was built using aluminized steel for the inlet flare. As you can see a good bit of the flared tubing has worn away. Aluminized steel is softer than 409 stainless steel.

 

Hmm. Was that damage cause purely by wear, or by a combination of wear and rust? The only real contact point of the flare is the donut gasket, which is constructed of a much softer material than even aluminized steel.

Oh, and no Dave, my Carsound doesn't look like that, or else you would have received an unhappy phone call by now.

 

Let me ask you, My car is making a very nasty vibration from the cat area...and it quiets down when the car warms up. Did yours do that? I thought maybe the stuff inside broke up.
I wonder ift thats my problem..cause I have the same cat.

 

I have no real vibration to speak of, and my cat. is around 2 years old now.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Padawan &raquo;</TD></TR><TR><TD CLASS="quote">I have no real vibration to speak of, and my cat. is around 2 years old now. </TD></TR></TABLE>dang, your lucky..Carsounds are very notorious for taking a dump after a year. Hec, My friend had his for a month..and out it went

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ScaleExtric &raquo;</TD></TR><TR><TD CLASS="quote">Let me ask you, My car is making a very nasty vibration from the cat area...and it quiets down when the car warms up. Did yours do that? I thought maybe the stuff inside broke up.
I wonder ift thats my problem..cause I have the same cat.</TD></TR></TABLE>

Mine is doing the same thing, but I am convinced that the cat is still good. I have tapped on it and it and the insides still seem to be intact and I have no CEL. I think I have traced it to the heatshield of the cat vibrating against one of the bolts connecting the b-pipe.

 

The HEAT shields are TACK welded to the CAT. there are 2 different metals attached together, they both expand and contract at different levels.

They have seperated at a tack weld, and are vibrating. have a muffler shop add some stitch welding.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris &raquo;</TD></TR><TR><TD CLASS="quote">The HEAT shields are TACK welded to the CAT. there are 2 different metals attached together, they both expand and contract at different levels.

They have seperated at a tack weld, and are vibrating. have a muffler shop add some stitch welding.</TD></TR></TABLE>

Thanks Chris, that makes sense. That would explain that only at certain engince temp am i getting a rattle...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">

Thanks Chris, that makes sense. That would explain that only at certain engince temp am i getting a rattle...</TD></TR></TABLE>Also..mine only does it at about 16-1700 rpms..what about you?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ScaleExtric &raquo;</TD></TR><TR><TD CLASS="quote">Also..mine only does it at about 16-1700 rpms..what about you?</TD></TR></TABLE>

yep, especially when i am letting off the throttle at a very low speed/rpm and the engine is cold...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris &raquo;</TD></TR><TR><TD CLASS="quote">The HEAT shields are TACK welded to the CAT. there are 2 different metals attached together, they both expand and contract at different levels.
</TD></TR></TABLE>

that is what mine did. i just ripped the heat sheld off. no more worries.

 

naa, mine don't look anything like that.

 

So which one do I have (bought from you in March of 2002)?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tommy_Gunns &raquo;</TD></TR><TR><TD CLASS="quote">So which one do I have (bought from you in March of 2002)?</TD></TR></TABLE>

I'm almost positive that Dave uses all stainless flanges/piping on his cats.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tommy_Gunns &raquo;</TD></TR><TR><TD CLASS="quote">So which one do I have (bought from you in March of 2002)?</TD></TR></TABLE>

I use 409 stainless steel tubing (same as cat body) for the inlet flare. The flanges are mild steel. I don't think anyone would want to pay the big extra $$ for stainless steel flanges for a cat, nor do you need them.

This is just a buyer beware post. If I get the time I may post something this weekend on the differences between purging the ID of the tubing during welding versus no purge.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">If I get the time I may post something this weekend on the differences between purging the ID of the tubing during welding versus no purge.</TD></TR></TABLE>

It's actually a nice coincidence that you mention that Dave. I've been looking into welding lately, and I remembered you had mentioned purging in a post quite some time ago. Something like that would be nearly impossible to locate with the search function.

Back to the original thread - did that flare show signs of rust at the damage site?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">Here's a picture of a cat that was built using aluminized steel for the inlet flare. As you can see a good bit of the flared tubing has worn away. Aluminized steel is softer than 409 stainless steel.

</TD></TR></TABLE>

Nope, but, I failed NYS emissions,,,,, ( the 1st time.)

35,000 miles I/H&E. Did the 30K tune up when required, car is in tip top condition...

We MADE it pass though!