Need real advice on Cat removal

I thought you could use an infrared non-contact temperature "gun" to measure the temperatures of the cats. They are a small chemical plant and if working right the temperatures will show that?

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

johnboneske said:

but that's a O2 sensor code. I have had that code before and it wasn't the CAT. There isn't any true code for a CAT. The only way to tell if a CAT isn't working properly or clogged is to remove the front O2 sensor and see what kinda pressure you get out of the hole... If you get a decent amount of air its clogged, as CATS don't have any back pressure associated with them.

Click to expand...

So a sensor designed to monitor the converter can’t generate a code to indicate that it’s bad? The definition of that code is “converter efficiency below threshold”. Which may or may not have anything to do with it being clogged. A converter can fail without clogging.

But yes, to check for a clogged converter you remove the upstream sensor. Very curious to hear from the OP on the results.

TomB985 said:

So a sensor designed to monitor the converter can’t generate a code to indicate that it’s bad? The definition of that code is “converter efficiency below threshold”. Which may or may not have anything to do with it being clogged. A converter can fail without clogging.

But yes, to check for a clogged converter you remove the upstream sensor. Very curious to hear from the OP on the results.

Click to expand...

Another way of testing the o2 sensors is using a scanner that provides you with live data. Bring up both s1 and s2 o2 readings, and look at the pattern. If the s2 frequency is following the same pattern as s1, that is showing that the oxygen isn't being converted into the proper gases. If you get a flat line for s2, that's usually a good sign that your catalytic converter is working properly.

Bad:
Bank 1 sensor 1
/\/\/\/\/\/\/\/\
Bank 2 Sensor 2
/\/\/\/\/\/\/\/\

Good:
Bank 1 Sensor 1
/\/\/\/\/\/\/\/\
Bank 1 Sensor 2
____________ <---- Flat line, gas is being converted properly.

If the O2 sensors have never been changed, change them! Those alone can cause power and economy to go down. They should be changed after 100K miles whether they throw a code or not.

ok to close this out, plugs, coils packs and fuel filter changed, ran 2 batches of catalytic converter cleaner thru and it got slightly better. Cats were $440 plus install so I paid $200 to have them removed, holy crap what a difference, its a little louder but not obnoxious, has a nice gurgle but power is better then its ever been. Check engine light is on but I don't care it has 237K on it so nobody's gonna care when I tell them why its on whenever I sell it. Thanks all for the inputs