Catalytic Converter Pinging?

[DVJ]

Catalytic converter pinging?

As exhaust systems expand and contract we will always hear little pops and pings in the exhaust train and the catalytic converter. My H2 at 3K miles has developed a very loud "ping" in the exhaust sytem when it is hot. The ping occurs at 15 second intervals. Audible within the vehicle at idle, it's like someone taking a hammer and rapping the metal housing. I have isolated it to the catalytic converter. Anyone having the same noise? It goes away in 5 to 10 minutes after I turn the engine off. It's an annoyance more than anything and gets the attention of folks at stop lights.

Regards,

DVJ

[DVJ]

Catalytic converter pinging?

As exhaust systems expand and contract we will always hear little pops and pings in the exhaust train and the catalytic converter. My H2 at 3K miles has developed a very loud "ping" in the exhaust sytem when it is hot. The ping occurs at 15 second intervals. Audible within the vehicle at idle, it's like someone taking a hammer and rapping the metal housing. I have isolated it to the catalytic converter. Anyone having the same noise? It goes away in 5 to 10 minutes after I turn the engine off. It's an annoyance more than anything and gets the attention of folks at stop lights.

Regards,

DVJ

[Grim_Smoker]

I'm not sure if I have the same noise, but I do have an odd high pitched metal rattling noise coming somewhere between the headers and in front of the rear doors, so it's probably the cat. It annoys the hell out of me too, and I'm hoping it won't be a problem to fix.

2003 Sunset Metalic Orange H2 - Breathless Stage 2B, HID's, Gobi Rack & Ladder.

2003 Millenium Yellow Z06

[MAC]

No such noise from my Hummer.
Only time I heard some sound from the converter was when the Hummer was brand new and within the first couple days, not loud at all, audible when parked in a quiet garage and upon exit of the Hummer. Only few couple days or so.

[HummerN23]

there are multiple posts on this here-try searching for exhaust noise. there is also a service bulletin on how to fix. I had the fix done a few months ago, it merely lowered the loudness of the popping noise for a while--noise is back now almost full strenght.

[Jigga]

My H2 made the same noise too. It's just the exhaust system when it gets hot. I've got 6k miles on mine and it had quit doing it so just wait and it will go away.

2003 Pewter H2 with Adventure Package.

The pinging noise or "poping" sound is caused by a defective muffler. Somthing with a broken weld or sheild inside the muffler. It can get very loud and GM knows about it. There is a TSB on this problem from GM. My H2 also did the same thing, the dealer changed out my muffler twice before the problem was fixed. Hope this helps! BIG-C

White 03-H2-LUX

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[DVJ]

Thank you everyone! Very helpful. Glad to know that I am not the only one.

I'll have the dealer listen to it when I go in for the oil change.

dvj

[Albie]

i have that same sound but I fig it cover fire when I get out......eheheheheeh

[AK47]

HI had the same problem then the noise got more and more,,,when it was cold it sounded like a tank anyway I cut open the cat and took it out welded it up and runs great

[Hellz]

Originally Posted by AK47

HI had the same problem then the noise got more and more,,,when it was cold it sounded like a tank anyway I cut open the cat and took it out welded it up and runs great

you are able to get away with that over there in the Czeck Republic.... we have laws here in the US that prohibit us from removing it. think it is about $2500 fine if you get caught with a tampered catcon.

i read about alot of tuners/off roaders who empty out the catcon. i thought about doing that to my H2.
buti'd prolly just get rid of the cat and run straight pipes to the muffler.

im all about getting the most performance, so if/when i do it, it will be when i put in new headers and a new exhaust system.

[AK47]

Well look here is the best way as I did it ok the H2 has to Cats ,,,so one at a time take of the front pipe that hold the cats now this bit is important the bulge area where the cats are make sure you cut into the cat from the top i.e. open it up cut in so you can wedged open like a flap from the top of the cat take out the brick filter ,,,push back the flap weld it up put some little paste round the weld ,,their you are the cats look like there still there ,,no one can see that you have de cated them as you cut in from above easy

[Hellz]

prolly easier to just take the cat system off and use a pry bar or a pipe and hammer and just crush the ceramic in there to empty it out. ya maybe a little more work taking the system apart, but no cutting or welding

[HumminNBoatin']

Wow talk about reserecting the dead with this old thread.

The cats in the H2 are notorius for failing. Mine failed on my 03 around 56K miles.

However I thought the Cats on the H2 where high flow straight through units??? This is what I have heard.... Can anyone confirm this? If they are in fact hi-flow cats there really is no performance gained buy gutting the cats. Also I would assume this should set a check engine light due to the post cat 02 sensors?

[HumminNBoatin']

Wow talk about reserecting the dead with this old thread.

The cats in the H2 are notorius for failing. Mine failed on my 03 around 56K miles.

However I thought the Cats on the H2 where high flow straight through units??? This is what I have heard.... Can anyone confirm this? If they are in fact hi-flow cats there really is no performance gained buy gutting the cats. Also I would assume this should set a check engine light due to the post cat 02 sensors?

[Braveheart7]

If it is effecting the ommissions frm exhaust they will probably change it for free.... mine is 74,000 miles 2005 and my onstar says still under warranty for smog up to 80000