With engine running,
I can hear fireworks sound + few smoke from this area see attached pic ?!
Same sound continues for about 10 minutes or less even after turning off the engine.
BTW CEL is off.
What you guys think?

 

if there are fireworks then you're most likely getting fuel in the exhaust past the cat's there might be a leak in the front y pipe. You should check to see if your car is running rich. Or you could be leaking oil or some other fluid on that pipe it looks like some sort of burnt oil residue on the front part.

 

sounds like its just the hot cats pinging as they cool down...

 

How to do that?

Have any one had this in his LS?

 

how loud is it? almost like a gun short? maybe the car is backfiring? when was the last time you got the spark plugs/wires changed?

 

cars cant keep backfiring after they've been turned off.

 

The crackling noise from the cats when they are cooling down is not a problem, it is simply physics at work and is not an indication of a problem.

If you started to notice this sound all of a sudden, and not since day one, then it probably isn't the cats cooling down.

I wish I could contribute more, but a "fireworks" sound is a pretty vague and subjective description of the symptom.

 

Does it sound like a gunshot of something?

How loud are these "fireworks"? Like the Grand Finale at the local park on the 4th of July... or firecrackers... or what?

 

Yeah, you could be running rich if the cats are really hot. Otherwise like's been said, it's just the sound of them cooling down. Smoke could be a different issue. Maybe you could describe it a bit more.

 

i had recorded this sound...
http://www.youtube.com/watch?v=6hQ4Vdfc6bw

So what it sounds to be?

 

If that was with the engine running (sounds like it), could be the cats expanding but it also sounds like something arcing. How long had the car been running when you recorded this?

 

1 hour.........

 

Prevoisly b4 1 week i had cleared OBD codes P0440,P0446
Today got CEL on with errors:
P0440 : Evaporative Emission Control System Malfunction
P0441 : Evaporative emission control system incorrect purge flow
P0446 : Evaporative Emission control system Vent control circuit Malfunction
I thing its related to my cats crackling sound? Any ideas what to do / check?

 

bump.
expecting great help.

 

Do i have to replace the Charcoal Canister?
Or i just can clean it to reuse it.
Please guide me!
attached file is the Charcoal Canister part from my 2000 LS400 repair manual in PDF format.
http://uploading.com/files/0O1FZZ3T/ec-5.zip.html