What could cause a clogged Cat. Converter?

[Hoags]

I have a question that I need answered, because I don't know for sure.
What could be the cause/causes of a clogged cat.converter? This morning I went the have the cracked windshield replaced and as I was headed home the car began to hesitate and blow excessive smoke. I pulled over into an empty church parking lot and looked under the car and I saw the prettiest red/orange glowing cat converter. ( i like the color it would make a great accent coleor for a graphic). I quickly shut down the car, and called AAA for a tow to Midas.

Prior to the melt down the car was not running all that bad, The hesitation condition when shifting was no worse that usual. But now I have some concerns as to the cause, is it an engine issue that will still be there to cause the replacement to eventually cook?

Any input is greatly appricated!
Thanks.

[grfnkl]

There's only a few things that cause this. If your car is running rich, fouled plugs (which will also cause the car to run rich), or bad exhaust valves. I'm sure there are other possiblities out there, these are the only that i know of. I know that they break down over time as well, but that's after many years. I'm going on my 2nd one, and nothing can be found wrong with my car... so go figure.

[Ridenour]

I would imagine also too much dirt being sucked in / passed through

and bad fuel with dirt in it burning off weird stuff and passing onto cat

[Hoags]

Thanks Guys, That info will help.

[Knifeblade]

U didn't mention how many miles on it or your driving habits. Stop/start city short hops wear and clog Cat.s faster than highway or several "road trips a month.

U got some very good ideas why, this is another.

They do wear, given time, but sans info. on above, I can't say if that is possible reason for what happened.

[Hoags]

Knife,
The front pipe and cat. were changed about a year ago and the cat. back about 9 months ago. I think that it is a faulty cat. that is one reason for the request. I want to have some amo on my side in case Midas gives me a hard time.

To answer your question I do some combination driving, since the replacement I would say that it is an even split between highway and start/stop miles.
The car has about 120,000 miles it is a 2.4L quad with a 5speed tranny.

I'm also concerned about this happening to the new cat. If something with the engine is causing this problem I want to take care of it. If any of this post sparks anymore suggestions I look forward to hearing from you and anyone else who may additional ideas,
Thanks,
Dan

[Knifeblade]

np, Dan, with the added info., I highly suspect a bad cat. installed. It would be good idea to check for your running lean or rich, though.

With the drive habits you state, 120K is still a little bit low for a cat. to plug up. do you get engine to operating temp. for say 10 minutes per drives?

Tam

[Knifeblade]

I'm leaning towards a faulty replacement cat., too, they don't plug up as you describe in one year, EVEN IF you running a bit rich, but they can do that if the exhaust doesn't get to it's heat running temp. to let the cat. use heat to help burn deposits through.

[Hoags]

Tam, Thanks for your input. I always make sure it gets to operating temp. I don't even let my wife shut it down early, I tell her to make sure that the car is up to running temp before shutting down. I feel that not letting it get to temp does more harm to an engine, you have to get to temp so nothing warps out due to temp variences.

[Knifeblade]

ayep, Dan, engines are meant and designed to run at operating temp.'s, and everything behind them, including the exhaust sytem is designed for that.

Tam