PCA SDR

My 98 boxster just failed smog in an epic way.... each reading was about double the max allowed. Looks like my cats are bad, sometimes it has thrown the code p0420 and the o2's only have about 10k miles on them so i'm assuming they're still good. Any advice out there? It looks like new cats are >$1k each which is tough to swallow on a car that is barely worth $11k (when it passes smog). On the flipside, anyone interested in a 98 spec-boxster candidate?

What were your numbers? High CO is usually due to running rich (due to old O2 sensors perhaps) and high NOx is usually due to high cylinder temps (vacuum leak perhaps).

You could try an additive called "Guaranteed to Pass." I had good luck with it in my 88 924S when I first bought the car. It essentially just cleans carbon deposits, but it did help my car idle smoother and may have helped with my numbers too. I did an 02 sensor and new vacuum lines at the same time, so I can't be sure what actually fixed the problem.

Is your Boxster a tiptronic?

every number was at least twice the max allowed.
and it is a regular old fashioned 5 speed.

If you need to go with new catalytic converters, check with some muffler shops. I had an aftermarket "high flow" one installed in my 944 for way cheap at Vista Muffler on Melrose in Vista. good luck.

lrayner wrote:If you need to go with new catalytic converters, check with some muffler shops. I had an aftermarket "high flow" one installed in my 944 for way cheap at Vista Muffler on Melrose in Vista. good luck.

You mean the one that just fell apart on us?

uhm yeah... but it did pass smog !

lrayner wrote:uhm yeah... but it did pass smog !

Yes it did! And we'll be without a cat until the next time we need to smog it.

lrayner wrote:If you need to go with new catalytic converters, check with some muffler shops. I had an aftermarket "high flow" one installed in my 944 for way cheap at Vista Muffler on Melrose in Vista. good luck.

I thought "High Flow" Cats are now illegal in Calif. I just had to replace mine and it has Numbers and Letters stamped on the Bottom portion of the Cat so the Smog Guy can read it. And yes, they broke out the mirror and checked.

The one I bought is made by Magnaflow and is a specific for California Specs.

I am doing this on a 99 Boxster right now trying to get around the factory cats.
Check back in a week.

But you need to have a Porsche specific shop with a PST2 tester to figure out your problem first!
Putting cats on a high emitting car will only destroy the new cats.

yeah, i got some cats, new maf, and 02's off of a friends wrecked boxster. swapped them all. car ran better and passed no problem. total cost: $300 plus an afternoon underneath the car.