Today was work on the Porsche 911SC day.
Changed the Oil.
Pulled the Seats. - Getting new skins this week.
Replaced the shifter bushing.

Then I decided to check the Cat because I have emissions this month and it has not been passing when I have tested it. Tried about everything that has been recommended, then I read that a bad CAT can cause you to fail. I think my CAT is original 122,000 miles and 30 years, so I am assuming that it will be be. My understanding is that when You take it off if you hold a flashlight at one end and cannot see light at the other it is bad. Is this correct? I didn't get it off today but I was able to bust all of the bolts hold the shield on. Actually I had to grind two of them off.

If I replace it I want one that just bolts into the place of the original. I have prices online from $395 to $1200. What have other used to replace their CAT.

Thanks,
Rob
1980 911SC

 

a piece of pipe

 

Glad to hear that smog is an issue in other states! You'll probably be fine with the new cat. I don't think you need to buy the expensive ones, a new cat of any sort HAS to be better.

 

I don't know a lot about the '80 SC, such as whether or not they had O2 sensors. But if you have the original Porsche cat, and the car has not been running too rich, it should still be good. The original Porsche cats were high quality metal mesh, not the ceramic like aftermarket.

I've heard of garage-made cats that cost as little as $300 that pass Calif smog, and I personally bought the $650.00 aftermarket cat. The oem Porsche one is now about $2,000 or so.

Some guys...(doo be do be doooo....) only run their cat at smog time, and otherwise run a cat bypass in order to run cooler and save the expensive cat for when you really need it.

 

yeah doesn't have one lying around in a garage they can ship to him for testing .. then ship back ?

 

post a link please - I just passed my cars "last" smog test... once 25 y/o no longer required

 

Ed I don't have a piece of pipe that is purely theorhetical as it would be bad for the enviroment. lots of info on cat bypass. in fact thay pop up on ebay once in a while.

 

Another member offered me a new in the box with OX Senor Cat for a reasonable price so I am going to do that and then go pass my emissions test. I hope. Car is running good so this should be the trick.

Thanks guys.

Rob

 

let us know how it works out