The cat dies, it'll let the dog out.

I'm not sure it does any damage to the car. It'll fail the inspect of course.

 

The cat dies, it'll let the dog out.

LMAO with this reply :lol:

 

Your vehicle exhaust gases will become noticeably more smelly.

 

Loss of power and fuel economy, hard to start.

 

Can possibly foul the o2 sensor and pull CEL.

 

Several modes of failure:

1. Meltdown - caused by too much fuel, typically plugs up and car feels quite doggy. Caused by ignoring CEL codes that make the car run rich. Can also result in clogging of downstream components, e.g. mufflers.
2. Substrate breakdown - see above, excessive back-pressure. This may be due to impact damage.
3. Catalyst breakdown, fouling - this will set CEL, but may not present performance issues.

Any of these will cause a fail in a I&M sniffer test.

 

Appreciate the replies and suggestions. But my problem is that my car's cat failure is intermittent. It shows up as TID $01 CID $01 test failure on scan. It sets the CEL but then after a while it'll go out by itself. (Happens mostly on Hot days, On cold days it goes out by itself and won't come on at all no matter what). So I was trying to understand if the cat fails then it should be bad at all times right?

 

if your cat is clogged, you will lose some power as less air is going through the "filter", if you run your car for extended periods of time with a clogged cat, the rest of your exhaust system will overheat and eventually fry some important stuff like the o2 sensor, newer cars have a primary cat in the exhaust manifold and a second one further down the exhaust somewhere, also you will fail emissions = no plate renewal

 

... see thats my problem. I want to know is that if a cat has failed it should be permanent. On my car the CEL comes on intermittently with code P0420 and then clears itself out. I am trying to figure out the problem by using the scan software. I haven't been able to repeat the cat failure after resetting the light using the software. So I'm confused whether its the cat or something else. It only happens on hotter days so am waiting for the whether to change so I get the CEL again and see what the system scan shows me.

 

No confusion necessary unless you like it that way.

In your Service Manual, there are diagnostic steps for each CEL.

 

im surprised no one has said this, but if my cat convert fails, i figure it is my cars way of telling me to go but a new high flow cat convert

 

@Frodo65,

I have about 122k on the car. Had replaced plugs at 115k (OEMs) and did a sea foam at 119k (didn't change the plugs after that). Sea Foam was done after resetting the CEL which originally came on well before that (I think around 105k). I'll check the basics and see where I stand with those and get back here.

But right now, can anyone tell me if the Cat has failed, will it be a permanent failure or an intermittent?

 

The ECU is telling you the cat is not doing its job. Given the price of replacement, I always go with the 'trust but verify' approach - eliminate the cheap, easy alternatives, and if the problem is still there, then bite the $$$$ bullet.

 

A buddy of mine had his cat clogged. It shit out burning crap all over the highway before the truck quit.
A Cat has to get to about 1000* F. Poke a cheap infared thermometer under there after it has run for awhile and see what you got. That is what my mechanic did for a quick and dirty test. I have also had Milage booster type gas additives kill the o2 sensors before. Never had that problem with seefoam but If your cat is hot I would try the o2 sensors first.

You could also cut it out and buy one of these http://www.o2sensorsimulator.com/

 

A buddy of mine had his cat clogged. It shit out burning crap all over the highway before the truck quit.
A Cat has to get to about 1000* F. Poke a cheap infared thermometer under there after it has run for awhile and see what you got. That is what my mechanic did for a quick and dirty test. I have also had Milage booster type gas additives kill the o2 sensors before. Never had that problem with seefoam but If your cat is hot I would try the o2 sensors first.

You could also cut it out and buy one of these http://www.o2sensorsimulator.com/

^^ not for those California boys lol

 

didnt want to make a new thread,

but will a high flow cat, pass a califorina smog?

 

I can't help you there, we don't have to smog test

I would think if they said it would it would. I read, don't remember where, that some do and some don't.

I would call the manufacturer.