Cat Question?

[Dillon]

How do you know when a catalytic converter is bad? Is there a code or is there a device for testing?

 

[basketranger]

limited knowledge here, that being said 1. if after driving a fair distance if she is cherry red she is bad. 2. take her to am inspection station that has a "sniffer: they can tell you. 3. unless you have an o2 sensor after the converter then i do not believe the engine computer can tell you. P.S. cats do not generally go bad unless the engine is pumping too much fuel (unburned) thru the exhaust. hope this sheds some kind of help.

 

[rangerboy92]

when mine went bad due to a ingition problem ( also dumping fuel) it would miss fire at low rpm wide open throtlle, then clear up above 2 grand

 

[Runnin'OnEmpty]

The engine will also be down on power and
won't rev. Like Basketranger says, it'll get
extremely hot.....

 

[SMTGREG]

On the 88 3.0 the check engine light would come on and set codes.
Catalyst system efficiency below threshold (Bank 1) - P0420
Catalyst system efficiency below threshold (Bank 2) - P0430
If the cat is restricted you lose power in high load situations. Use a exhaust pressure gauge or loosen the exhaust flange before the cat and see if it runs better.