How can you tell if your Catalytic Converter has gone bad?

Question

I have a 2002 Jeep wrangler with over 110,000 miles, sometimes there is a weird sulfur like smell that comes out (no smoke).

Also, I have a 1987 Porsche 928 S4 with 70,000 miles, and when I first start it up, blueish-grey smoke comes out of the tail pipe.

Answer 1

first of all it is easy to tell if your catalytic converter is plugged because your car jerk and stall. the sulfur like smell is most likely a blowen exhaust manifold gasket the blueish smoke out the tail pipe is most likely is a blowen head gasket

Answer 2

Blue-gray smoke is normal on an older vehicle if it has been sitting a while. It has to do with engine wear, and not the catalytic converter.

The Jeep likely doesn't have converter problems yet. The gasoline you are using has a high sulfur content. Try changing to a different brand for a couple of tanks and see if it makes a difference.

If you had a bad cat, you would notice problems upon hard acceleration from the backpressure, but would be able to gently accelerate with no problem.

Answer 3

a strong sulfer smell is almost always a bad catalytic converter.

on the porsche you most likely have bad seals somewhere. the blueish smoke is oil burning. when you let is sit oil is slowly leaking into your cylinders. it's still safe to drive, but you'll need a rebuild in the future.

Answer 4

Catalytic converters will make the engine seem "constipated" when they start to clog up.

When the cat converter clogs bad enough the engine will stall or backfire through the intake manifold from not being able to breath correctly...

Does this info help any?

Answer 5

The helpful-fire way is to get a smog verify or a diagnostic from a save that could attempt it. The operational verify is to verify if it has any limit or blockage. some autos (like Fords) have a ceramic honeycomb that could injury up in chunks and block the exhaust. you are able to consistently replace it and understand that's sturdy.

Answer 6

the catalitic converter is basicly like an oven, air is pumped in and all the unburned hydrocarbons are burned up at about 700-800 deg
if you get a infered temp guage just see how hot its getting, if its as hot as the rest of your exaust its not working

Answer 7

Take it to a mechanic to make sure, but that sulfury, rotten-egg smell is usually a dead giveaway that your catalytic converter is bad.

Answer 8

It is time to replace your convertor, usually at 100K it is time to replace them. As for the blue smoke in your porshe, that is burning oil, oil leaks down from the valve seal and when you start your car you burn the oil right away...

Answer 9

if it smells like rotton eggs,then its bad.and for the blueish gray smoke,its probably valve seals.

Answer 10

take it to a pro mechanic for a test to see.