Catalytic Converter dead - 986 Forum - The Community for Porsche Boxster & Cayman Owners

jb92563 · 10-23-2015, 06:43 AM

I got the engine light for the dreaded dying catalytic converter P0430.

I have a CA smog inspection due by Nov.

I tried the "Guaranteed to Pass" fuel additive. No Luck.

I tried replacing the down steam sensor even though I could see on the Durametric that it was following the upstream voltage sine wave instead of a strait line as it should be, indicating the CAT is dead. No Luck.

I only have that P0430 code so its not likely anything else.

I discovered that there are electronic devices that emulate a proper functioning downsteam sensor for a good CAT, but if a tailpipe sniffer test is used and they stick the probe in the passenger side exhaust they will likely detect excessive emissions.

However I could reinstall the downstream CATs and it would likely pass with the Electronic cheat (~$70).

But in the end its an inconvenience to reinstall the rear CATs every 2 years.

So it would be better to buy a replacement passenger side Header CAT.

I suppose I could buy a used one, which I prefer at this point to save some bucks, or I could bite the bullet and buy a new ~$1800 CAT.

Are there any other options I have overlooked?

Does anyone know of a used one for sale?

What is the best price/site for buying a new CAT?

JFP in PA · 10-23-2015, 07:04 AM

Quote:

Originally Posted by jb92563

I got the engine light for the dreaded dying catalytic converter P0430.

I have a CA smog inspection due by Nov.

I tried the "Guaranteed to Pass" fuel additive. No Luck.

I tried replacing the down steam sensor even though I could see on the Durametric that it was following the upstream voltage sine wave instead of a strait line as it should be, indicating the CAT is dead. No Luck.

I only have that P0430 code so its not likely anything else.

I discovered that there are electronic devices that emulate a proper functioning downsteam sensor for a good CAT, but if a tailpipe sniffer test is used and they stick the probe in the passenger side exhaust they will likely detect excessive emissions.

However I could reinstall the downstream CATs and it would likely pass with the Electronic cheat (~$70).

But in the end its an inconvenience to reinstall the rear CATs every 2 years.

So it would be better to buy a replacement passenger side Header CAT.

I suppose I could buy a used one, which I prefer at this point to save some bucks, or I could bite the bullet and buy a new ~$1800 CAT.

Are there any other options I have overlooked?

Does anyone know of a used one for sale?

What is the best price/site for buying a new CAT?

The price on new cats are going to make your eyes water, so I would consider used cats out of a wreck. We have installed several sets of these for customers and had great results. Check the boneyards in your area for price and availability.

jcslocum · 10-23-2015, 07:46 AM

There are weld in replacement cats...

Would that be a legal option?? It may also keep you from unbolting the manifolds.

Gilles · 10-23-2015, 11:05 AM

Quote:

Originally Posted by JFP in PA

The price on new cats are going to make your eyes water, so I would consider used cats out of a wreck. We have installed several sets of these for customers and had great results. Check the boneyards in your area for price and availability.

Unfortunately in CA the wrecking yards will not sell you a used cat (according to them it's against the law..) can you buy generic cats and get them installed by a muffler shop?

I have done this on the ALfa and they worked well (@ almost 1/2 price than the OEM type), good luck.

tommy583 · 10-23-2015, 11:31 AM

Have Woody send you a used set. If you don't know he can be reached by PM on here, itsnotanova. I'm sure he can hook you up for a great price.

thstone · 10-23-2015, 12:02 PM

Buy a used cat. I got mine from someone here on the forum or check eBay. I swap them in every two years for the test and then remove.

NewArt · 10-23-2015, 02:30 PM

Check Woody or else eBay is your friend. I've done this, easy-peasy!

hancock1701 · 10-23-2015, 03:10 PM

I recently went through this, and luckily my cats were still well enough to pass without me having to do anything.

I tried to contact Magnaflow for their universal catalytic converter for our car for the exact dimensions, but they didn't get back to me. Their cats are CARB approved for this car, so 100% legal.

I thought about having a shop cut the integrated catalytic converter off the exhaust manifold, then weld the universal one on, but looks like there's almost no room to fit all this back in. But you might be able to find a muffler shop that can try.

jb92563 · 10-23-2015, 07:03 PM

I took a look at Ebay and to my surprise there were quite a few available so I ordered one that had 45K miles on it and the guy stated that he tested them and they are working well.

If not there's Paypal buyer Protection and I'll return them.

I assume the headers have a gasket so I better order that next.

Any know of any tips or tricks I should know about when trying to remove/replace the headers?

Ray

NewArt · 10-23-2015, 07:44 PM

Seeing as you are in California, you probably won't have much trouble unfastening the bolts. You will need the header and triangular gaskets to do the swap.

Slate 01 · 10-24-2015, 05:57 AM

If you have friends or family that live outside of california, buy and send to that person, then have them send them to you. They will be the same cat that is sold in california sans the california sticker.

I did this a couple of years ago on a non p car. Instead of paying 800 bucks I paid 175 bucks, problem solved with zero problems.

Lapister · 10-24-2015, 04:50 PM

Noticed your car to be 01 and in Ca now for 2000 and newer cars it's the OBD2 plug in test. 99 and older still get the sniffer. C.L. Has used cats too.

jb92563 · 11-09-2015, 12:00 PM

I installed the used (45k Miles) CAT/header and hooked up the Durametric and I get the proper wave form showing that the cat is working as it should. Hurray.

Again I was surprised how easy this was to do myself.
Less than 2 hours with a good amount of time wasted trying to get to the rear O2 sensor plug released.

I've driven over 6 days to work and back over 150 miles and no check engine light so far so I'll take it for the smog later this week and see how it does without the rear 2nd cats installed.

I noticed on the old cat that the cat unit inside seemed to slide back and forth in its can, probably allowing exhaust to escape past the matrix.

Is there any residual value for the header/cat at this point?

Should I just throw it out or save it for next time and have an aftermarket cat element welded in at that time?

epapp · 11-10-2015, 09:37 AM

How do you keep the CEL happy with the cats removed?

Quote:

Originally Posted by thstone

Buy a used cat. I got mine from someone here on the forum or check eBay. I swap them in every two years for the test and then remove.

thom4782 · 11-11-2015, 07:00 AM

[QUOTE=Gilles;470858]Unfortunately in CA the wrecking yards will not sell you a used cat (according to them it's against the law..) [OUOTE]

Gilles and the wrecking yards are right. The California Air Resources Board prohibits the sale or installation of used catalytic converters in California. That's why wrecking yards don't advertise them and shops generally wont install them

JayG · 11-11-2015, 07:08 AM

There are some low cost CA legal replacements available
Search - 250-24647 250-24647 250-24647 250-24647 441204 441204 441204 444204 444204 444204

jb92563 · 11-12-2015, 11:56 AM

Quote:

Originally Posted by epapp

How do you keep the CEL happy with the cats removed?

Since the California cars have 2 cats per side, only the upstream cat on the header has sensors. I removed the downstream cats when I did my 2nd cat delete and Top Speed muffler install.

Since the upstream sensors and cat are functioning fine no engine light.

I also just passed the smog yesterday.

Apparently the Test has changed and for 2000 and newer, as mentioned in this thread, they don't use the tailpipe sniffer anymore, so if all your pollution codes on the computer are good then you pass.

My smog literally took 5 minutes as one guy hooked up the OBDII cable and the other guy took a peek under the rear.

Seems like $60 is too much now for that little work.

I think the next step if that you hook up your own computer to the OBDII and send your report directly to the DMV without the middle man.

Ray

epapp · 11-12-2015, 11:59 AM

Ah, right. Us with the <'99 have to live with one cat per side as usual then. You got me excited.

Smallblock454 · 11-12-2015, 12:20 PM

Quote:

Originally Posted by jb92563

I think the next step if that you hook up your own computer to the OBDII and send your report directly to the DMV without the middle man.

That would be great.

Regards, Markus

Porsche9 · 11-12-2015, 01:06 PM

Quote:

Originally Posted by jb92563

Since the California cars have 2 cats per side, only the upstream cat on the header has sensors. I removed the downstream cats when I did my 2nd cat delete and Top Speed muffler install.

Since the upstream sensors and cat are functioning fine no engine light.

I also just passed the smog yesterday.

Apparently the Test has changed and for 2000 and newer, as mentioned in this thread, they don't use the tailpipe sniffer anymore, so if all your pollution codes on the computer are good then you pass.

My smog literally took 5 minutes as one guy hooked up the OBDII cable and the other guy took a peek under the rear.

Seems like $60 is too much now for that little work.

I think the next step if that you hook up your own computer to the OBDII and send your report directly to the DMV without the middle man.

Ray

In the Phoenix area the state does the test eliminating the middle man. 5 minutes and $24 later I'm out of there chuckling about the guy trying to look under the car and not realizing the secondary cats aren't there.