Catalytic converter testing

[Skyler]

Hi everyone,

I just performed a temperature test on my TJ with a infrared thermometer reader after driving my Jeep for a good hour around and about.

when I pointed the laser at the front cats(inlet I’m assuming is what it’s called?) that are attached at the manifold I’m getting around 400-500+ degrees F depending on where I point it but that’s the rough reading temp. Then when I point the laser at the rear cat I’m getting a reading of around 250 fahrenheight ?

Is this a indication that the catalytic converter needs replacing or ?

 

[Chris]

Your cats shouldn't be that hot. When they do get that hot, that is indeed a symptom of failing cats.

 

[Skyler]

Your cats shouldn't be that hot. When they do get that hot, that is indeed a symptom of failing cats.

Hi Chris,

what could cause this to happen before the catalytic converter if anything? Could a leak in the exhaust manifold/gasket cause the temp to be this hot?

 

[Chris]

Hi Chris,

what could cause this to happen before the catalytic converter if anything? Could a leak in the exhaust manifold/gasket cause the temp to be this hot?

I don't think it's happening before the cats, I think that it's likely just the bad cats and heat from them is radiating everywhere else.

I guess another possibility would be your engine is running too lean, but that wouldn't cause the type of temperatures you're seeing I don't think.

 

[Skyler]

What causes an engine to run too lean?