2001 S catalytic converter question

[Dave2001S]

Is there a good way to tell if a catalytic converter has been contaminated or has gone bad?

[tcora]

Originally Posted by Dave2001S

Is there a good way to tell if a catalytic converter has been contaminated or has gone bad?

You should get a MIL (aka CEL) light from the OBD2 system if the cat is bad.

[turboflyer]

Originally Posted by tcora

You should get a MIL (aka CEL) light from the OBD2 system if the cat is bad.

Unless the 02 sensors post cat are at fault. How many mile on the system?

[paulv]

Originally Posted by Dave2001S

Is there a good way to tell if a catalytic converter has been contaminated or has gone bad?

Couple of things you could do:

Lightly tap (with something like a rubber mallet) the shell to see if you get any rattles -- this would show you if the wrapping insulation is loose of the substrate is falling apart.

Remove the front O2 sensor and attach a pressure gauge (low pressure, like up to 15psi or so) -- at idle, the pressure should be around 1-2 psi -- for a snap throttle test, the pressure in general shouldn't exceed 4psi, if so, there's blockage in the cat.

Regards,
paul...

[Dave2001S]

Thanks a lot for the replies. The car has 138K miles on it. I recently acquired it, and therefore the previous owner had it smogged as part of the title change; which it passed. The tapping test is good suggestion, I'll try that.

[rujorujo]

I just did cat replacement on my 01 986 S. Cat declared dead by Porsche shop. I did entire exhaust system replacement myself (front cat integrated in header). Parts expensive - it pays to shop the web. Removal and installation not difficult, but very dirty, and no special tools required - can be done in an afternoon.

Also did MAF sensor replacement (Need #20 security TORX, available at Home Depot), and cleaned throttle body.

Passed CA smog and running fine.