Should A Cat Be Going Out After 100k?

[SPORTcoupe300]

I heard some sounds coming from underneath the car the other day that sound all too familiar.

This is my first Lexus and so far I have not heard a single person ask anything about the catalytic converter except where to find a high-flow aftermarket one.

Definitely sounds like mine might need to be replaced sometime soon.

Is this a normal time for it to go out?

Also, HAS anyone found any high-flow cats sold separately.

I've seen them sold with whole CAT-back systems but I'm happy with the sound of the stock mufflers.

Let me know what you guys think.

I'll probably stop by at a mechanics to verify that it's the cat either today or tomorrow.

[jzz30]

they sell high flow cats every where and your right the stock mufflers sound good as they are

[SKperformance]

just wondering

it what regards are the noises

as even a dead one doesn't make noises

are you sure it is not the heatsheild rattling or something

have you done an emission test to see if it is dead?

as the ecu for the car has multiple 02 sensors

before and after chaning the algorythm by going rich and lean

and it monitors the one after the cat to make sure it is working right by seeeing if it is a stable fuel adjustment rather than following the patttern of the ecu

[AWJ]

SK is right. What kind of noises are you hearing. The SC exhausts are notorious for clicking and pinging after shut off while the exhaust cools down. It is just the heat shields expanding and contracting. It's normal. My 93 did it all the time, but the 95 doesn't mainly because the exhaust is a one off custom and there are no shields. ;)

[SPORTcoupe300]

The ticking noises(while cooling down) I know pretty well and they do seem to be quite a bit louder in this car than in any other I've owned.

The noise I hear coming from what I think if the cat is a slight rattle/ping noise at around 2.5k rpm when giving the throttle a quick tap.

I'm guessing one of the plates inside the cat is loose and it only rattles when you quickly accelerate.

If I ease the pedal slowly down, I can go the whole range of RPM and not hear a noise.

But then all i have to do is let it idle, then tap the accelerator so the RPM jumps and I hear the rattle.

So I can pretty much buy any universal high-flow cat (that fits of course) and it will work fine?

Also I went to the DMV today to transfer the car and they told me I need to smog it which I'll prolly do either today or monday and let you guys know if I pass(or not).

[SKperformance]

i have to agree that all lexus toyotas do make that noise on the cooling exhaust and heat sheild

but i would say it is something like the sheild being loose rather than convertor because of the multi sensors

put it on a hoist and listen i bet it is one of the multiple sheild that are under there

over the cat or resonator

as the 2500 rpm suggest that it creates a frequency vibration which is hard to hear from a cracked internal cat( but possible)

since it is not real low in rpms is suggests a higher freuqency towards something lighter to be able to move easier

i know that makes little sense

but check the sheild

it may even be the last owner ran soemthing over and loosened one on the manifold as it also has many heat sheilds

[SPORTcoupe300]

So I smogged the car yesterday and it passed, suggesting that the cat is functioning.

My mechanic only works monday-friday, 9-6...the exact same hours I work.

Guess I'll have to take a day off to go lift the car so we can find that stupid rattle.

I'm pretty sure it is one of the heatshields but it's a pain to find which one, especially when the car is hot. =)

Thanks for the suggestions.

[SKperformance]

glad to hear it is much simpler than first thought so far

good luck

[UCF3]

I'm experiencing the same from my SC cooling down. I wonder if it has anything to do with age of the Cat?

Anybody own their SC's when it was brand new?

[SKperformance]

when i first bought my es it used to make that crakling popping noise all the tiem for like 15 minutes

when the car was 2 years old

the heatsheild usually needs vibration to make it noisy from the engine running

[SPORTcoupe300]

So my mechanic is now too busy for me.

He said that I can go ahead and bring in the car but he has no place to put it.

That's not what I wanted to hear since I wanted to be there when the car gets raised.

Oh well, decided to do it myself.

I hate jacking the car up because I have this little cheap Kragen jack that only lifts like a half a foot.

For changing the oil and stuff underneath the car where I don't have to touch the wheels I have these ramp type things that I just drive up and then there's plenty of room to work underneath the car.

Well I did that yesterday and tried to find that noise coming from the exhaust. NADA.

I guess because of the strange position of the car, whatever was loose and rattling, no longer was.

Difficult to fix a problem when it can't be reproduced.

Tossing it into my bag of "Future Fix-it Problems"

[SKperformance]

gotta love that kinda problem

i work for the phone company and when ever i go to someones house

they always say, why couldn't you have come yesterday

now it works fine the ( buzz ,static ,hum no dial tone ) is gone

lmao