Do cats need a "break-in" period? Emission related

[InvalidUserID]

I ask because I just had my CA emissions test and to my surprise, my NO measurement went down as well as my HC count. At the time of my last test, I had just replaced the cat converter and had put maybe a couple hundred miles on it before the test and these were the results:

In those two years, I've done MAYBE 10k, one oil change with the same oil/filter combo, and a coolant flush...that's it. The results from today's testing are:

With everything just about the same (both times cars were driven on the freeway prior to the test, car didn't sit before test), the only thing I can think of is the cat needed a break-in or the coolant was bad and the cylinders weren't cooled properly?

Either way, glad I passed...opinions on the readings?

EDIT: This is on my 3800 II 1996 Camaro with 180k miles.

 

[JHZR2]

temperature changes reaction rates and efficacy of conversion.

 

[PandaBear]

I don't think catalyst need break in, but your engine control may need some time to relearn the calibration if things are changed (or you have to reset the ECU).

Also I wouldn't put too much faith in the measurement tool of the smog places. A lot of them are not very precise and vary from places to places.

 

[Vikas]

Your NO numbers are still way over average. Could the EGR be culprit?

 

[InvalidUserID]

That's what I'm thinking as well considering the cat is still new.

EGR was replaced probably 6+ years ago so it is a possibility. In all honesty, it hasn't thrown a code or failed an emission so it isn't a super high priority. Probably one of the "when I get around to it" jobs.

 

[StevieC]

What kind of car & mileage are we talking... Looks like a lazy, bad or plugging up EGR system to me.

Could also be the wrong temperature thermostat eg: 195 instead of 192 or 188.

Could also be too high heat range on the spark-plugs.

Otherwise the numbers are excellent.

 

[Scott_Tucker]

Cats do 'break-in' but they do not work better with age. Cats are extremely efficient when they are brand new but that efficiency quickly levels off and stabilizes at a lower lever. If you are having performance equipment CARB certified in California the cats have to be 4 months old minimum before you can use them on the test or they have to be 'seasoned'. I was at a CARB certification lab in southern California and they actually have test engines on dynamometers that continually run in a preset drive cycle for days on end to season cats for the O.E.M's before they have new cars emission certified. I would not be too concerned with your readings as the numbers can change from day to day. Just be glad you're set for two more years.

 

[rslifkin]

So California thinks it's ok to waste fuel and create unneeded pollution by running an engine for days on end just to "break in" a cat, but people can get in trouble for replacing a muffler?! Makes no sense to me...

 

[Scott_Tucker]

The purpose is to decrease the efficiency of a new cat until it stabilizes. Then the car can be tested. This results in much less pollution in the long run.

 

[rslifkin]

I guess. Why not just have the buyer of a new car come back for a test after the first 1000 miles or something, and the dealer will fix any issues that arise?

 

[PandaBear]

Originally Posted By: rslifkin
So California thinks it's ok to waste fuel and create unneeded pollution by running an engine for days on end just to "break in" a cat, but people can get in trouble for replacing a muffler?! Makes no sense to me...


The "running an engine for days" is part of a test that any engineering and design work in any field has to do. You should see how API tests engine oil, they are just like this, maybe more.

I've never known anyone get into trouble for replacing muffler unless it is a cherry bomb that barely muffle any sound. You get a fix it ticket for owning a loud car, not fixing it.

 

[PandaBear]

Originally Posted By: rslifkin
I guess. Why not just have the buyer of a new car come back for a test after the first 1000 miles or something, and the dealer will fix any issues that arise?


Because the car manufacture already tested it and based on the data it should last more than 8 years 100k miles (or something like that). When they design the car they sure as heck burn in the cat before testing it too.

 

[StevieC]

Originally Posted By: rslifkin
So California thinks it's ok to waste fuel and create unneeded pollution by running an engine for days on end just to "break in" a cat, but people can get in trouble for replacing a muffler?! Makes no sense to me...
It's the sun everyone there is half-baked.

J/K of-course...

 

[XS650]

Originally Posted By: rslifkin
So California thinks it's ok to waste fuel and create unneeded pollution by running an engine for days on end just to "break in" a cat, but people can get in trouble for replacing a muffler?! Makes no sense to me...


Are really that obtuse or do you just play a mowron on the internet?

 

[rslifkin]

XS650 - I understand the concept behind it, but does every cat that goes on every new car really need to be pre-broken in?

 

[mechtech2]

Originally Posted By: Scott_Tucker
Cats do 'break-in' but they do not work better with age. Cats are extremely efficient when they are brand new but that efficiency quickly levels off and stabilizes at a lower lever. If you are having performance equipment CARB certified in California the cats have to be 4 months old minimum before you can use them on the test or they have to be 'seasoned'. I was at a CARB certification lab in southern California and they actually have test engines on dynamometers that continually run in a preset drive cycle for days on end to season cats for the O.E.M's before they have new cars emission certified. I would not be too concerned with your readings as the numbers can change from day to day. Just be glad you're set for two more years.


Right. Cats are best when brand new.

 

[Scott_Tucker]

Originally Posted By: rslifkin
XS650 - I understand the concept behind it, but does every cat that goes on every new car really need to be pre-broken in?



I think you misunderstood. New cars do not have their cats broken in. It's just the cars they use to get the California Air Resource Board to certify that their vehicles are emissions compliant. This is part of the R and D process when they are designing the car.

 

[rslifkin]

Ok. The way it was phrased initially, and with how strict California is, I thought you meant that every individual car had its cat broken in, and then the car was tested for compliance.

 

[Gary Allan]

Yeah, it's not like there's a "cat break in industry" just hooking up new cats so that they're suitable for consumer use.

It's for all kinds of stuff. An opacity meter for an oil fired boiler may cost $2400 from the manufacturer. To get PA approval, it has to pass so many tests (that the OEM must pay to have performed) for DEP certification ..that the price jumps to $16k