olddog

iTrader: (2)

I have been buggging you LS guys with some of my problems recently and i appreciate your help.But i have one last question in order to solve my last problem and my LS should be ready to go in for the planned makeover.
here goes..
i have this sound coming from under the engine and i thought it was very much an exhaust leak. i took the car in and it was raised up. we found one hole in the exhaust right where the Y pipe meets joins the end of the cat. converter.
it was welded(am not sure if done properly but a significant amount of the hole was covered).
i still get this sound which sounds like there is a hole in the exhaust system.or like there is a handful of gravel/pebbles dancing around in the front part of the exhaust whenever car is revved. it is either coming from the cat. converter in the middle or pretty much from under the engine in front where i believe there are two more cat. converters. it definitely is from the front half of the car.
i have gotten two mechanics who said it is the cat. converter and that it is expensive to replace. but i read through some searches on CL about removing them altogether or so.
My question therefore is; is it possible to remove the cat. converters and just replace them with pipes? Can this removal also apply to the two cat. converters under the engine. i just need my exhaust to be normal again. And btw no lights/ warning or stuff like that are coming up on the dash.
anybody else have any experience with this.
i hope i described this sound to an understandable extent.
thanks in advance.
this is just the last thing to fix before car goes in for a total makeover.

PureDrifter

iTrader: (10)

the exhaust on the LS is arranged as follows:

Header--Catalytic Convt.--\_________________________________/Muffler---Resonator---tips
_______________________-Center Muffler (3rd cat on rare cars)--
Header--Catalytic Convt.--/_________________________________\Muffler---Resonator---tips


so was ur hole in a muffler or the cats?

olddog

iTrader: (2)

Hey,
I believe the 92 ls400 has one of those 3rd cat on rare cars you described, right?
The hole was right in the pipe which connects the 3rd cat and the the mufflers at the back. if i were to loacte where the hole using your diagram above, i would say right after the two "--" which come after (3rd cat on rare cars).
The hole was welded nicely and even if there was still a little hole left, it shouldn't sound the way it does.
i can't wait to find a resolution. the anxiety of a paint job is killing me

PureDrifter

iTrader: (10)

actually it is NOT model year dependant. some cars had it others didnt.

and to clarify, ALL LS400s have SOMETHING there, on MOST cars it is just a center muffler, on a few rare cars it is a 3rd Cat.



only an exhaust shop can help you man, i just tossed my OEM exhaust and had a custom setup made

olddog

iTrader: (2)

thanks for your input.

guitarmike

definitely sounds like a cat coming apart on the inside. The honeycomb structure on the inside tends to break down ovefr time and begins to rattle sort of. When you described it as rocks in the exhaust that is a dead give a way of a cat coming apart.

olddog

iTrader: (2)

is it possible to eliminate these cats?
i also read somewhere on the internet how they are rebuilt by being cut open and stuffed with some brown foam material(i think the knd that goes in between walls in houses for insulation) to stop the rattle ans sound. how true is that?

Thermactor

iTrader: (1)

that sounds like bull****, you can take a cat off and look right through it and it would be very easy to tell if someone filled it with stuffing

JimsGX

You may want to check out this manufacturer of OEM and aftermarket exhausts. They have distribution sites in the US and Canada (Ontario) and distribute through NAPA in CN... The prices are list. I would think you could do much better than that... If the prices aren't listed when you choose the CN search, try the US search. I found more of the prices listed in US dollars.

http://www.bosalna.com/index.php?mod=catalog