Does a catalytic converter need to be "broken in" before smog testing?

Emission · Emission's Garage

I purchased a brand-new CAT for my Porsche so I can pass smog cleanly this time (my other CAT had literally melted inside-out). It is bolted on now, and I want to run over and get the car smogged.

My question: Do I have to put XX miles on it before it works properly? I know it needs to hot (heated to operating temps), but are there any other things I need to do before it works?

Goth · 10-14-2006, 10:20 AM

Should be good out of the box. Last weekend, had my truck smogged about 2 hours after a new Cat was installed (Cat on, got some lunch, then passed smog with flying colors). FYI: I did take it down the freeway about 4 miles just to get it hot and burn the new stink off of it.

Emission · Emission's Garage

Quote:

Originally posted by Goth
Should be good out of the box. Last weekend, had my truck smogged about 2 hours after a new Cat was installed (Cat on, got some lunch, then passed smog with flying colors). FYI: I did take it down the freeway about 4 miles just to get it hot and burn the new stink off of it.

Thanks!

After I slapped it on late last night I zoomed over to the grocery store leaving a trail of smoke and sulfer smells... I think it is clean now (at least my garage doesn't stink!).

Goth · 10-14-2006, 10:34 AM

Good Luck!

Quicksilver · 10-14-2006, 01:36 PM

If you are worried about the smog just make sure that the car is completely warmed up. Go drive it for 1/2 an hour before you pull in to the station.

88911coupe · 04-29-2009, 07:48 AM

Other than checking to see if it's clear, is there any way to "test" a cat? I passed emmissions fine before I did my rebuild so I'm assuming I don't need a new cat but I don't know how old the one is that's on the car ('88 3.2). If they are not obviously clogged and the car still passes smog fine is there any damage they may cause just by being old?
TIA

scarceller · scarceller's Garage

Cats often fail because of rich mixture, just be sure your base CO is set correctly and that the car is not running rich. When you failed what failed? and what was the HC number?

88911coupe · 04-29-2009, 12:23 PM

Sal, just to clarify, my '88 passed smog test fine about a year ago when I last took it in just before starting the engine rebuild. I'm just assuming that I don't need a new cat, based on the fact that my emissions have been in spec.

scarceller · scarceller's Garage

Here in RI they only test CO and HC on these older cars. My 84 car has NO cat it has SSIs with 2in2out pipe it passes RI smog with no problem! But if they tested NOX I'm sure I'd fail. What did you fail? what are they testing in Texas? CO, HC and NOX?

poc533 · poc533's Garage

I just went through the process of smogging my 86 Carrera. I failed the 1st time, and on the 2nd test I passed.

In my opinion you should do the following to make it easier to pass smog

1) If you have it, make sure you put in the factory chip. I had a Wong chip in for my 1st test. After failing I e-mailed Steve, he recommended that due to stringent California regs that I use the factory chip.

2) Make sure the cat is good and hot. for my 1st test, I ran the car for about 5 minutes and drove the mile to the test facility. For my 2nd test, I made sure the cat was hot. Let the car run for 30 minutes or so before testing.

3) Suggest for the California test you also make sure your fuel cap and related evaporative cannisters are good and that you know where all the components are. I failed the evap test the 1st time. I did some research the 2nd time and was able to show all the related evap devices to the tester the 2nd time.

Hope this helps.

Porsche-O-Phile · Porsche-O-Phile's Garage

Get it hotter'n'hades - I doubt just driving a half hour is enough. I'd put at least 5 hours on the new cat and then at least an hour of run time before taking it to the smog shop. But I'm paranoid like that.