Red hot catalytic converter?

2002 JEEP GRAND CHEROKEE
170,000 MILES • 4.0L • 6 CYL • 4WD • AUTOMATIC
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DWMAZURJR
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The #2 bank catalytic converter is getting red hot.
Sep 15, 2021 at 1:29 PM
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SQM
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Hello,

Typically you will have an overheated exhaust component if there is a restriction.
If the exhaust gases cannot escape properly it will build up pressure and heat inside the system.
Usually the restriction is just after the overheated component.
You can use a infrared heat gun to find the spot where there is a significant temperature change, as likely the restriction is right before that spot.

There is a good change you might have a clog/restriction right after that converter.
As you know the internals of the converters can come loose and restrict the air flow.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

You might have to take off that pipe to have a look.

Please let me know of any questions.
Thank you.
Sep 15, 2021 at 2:16 PM
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JIS001
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Hi, just to jump in, have you had a chance to scan the computer for codes. If you have not then here is a link on how to do it with a scan tool.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Now if you have a scan tool and you are able to read live data I would look at the intake temperature sensor data. While cruising around 40 MPH and no cars around you with a co pilot looking at the data. Hit the accelerator pedal down to the floor. If the intake air temperature sensor climbs up a few degrees then yes, investigate for a plug exhaust. If the temperature goes down a few degrees then there is no restriction. Sometimes the upper oxygen sensor can get stuck causing too much fuel or not enough fuel to pump. When an 02 sensor is stuck it should post a fault code, either a current or pending code.
Sep 16, 2021 at 9:09 PM
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