Only PO430 driver side?

Ok, so the PO430, found out, is for the driver side, and I keep putting stuff in it and with in a month it's back, and it stinks.
The PO420 is for the passenger side, but why does the driver side cat keep going bad and not both.
Here is what I tried:
Best catalytic converter cleaner Kit effective foam spray motorpower care | eBay
It's more expensive on Amazon I think. You have to unscrew, unclip your upper o2 sensor and put it in. I did it to both, and it worked better on the passenger, but came spuing out the hole on the drivers side, but eventually went in.
The cat has to be a little hot, so run the truck and let it cool down for 30 minutes, it has to dissolve the foam.
SO WHY DOES MY LEFT CAT KEEP GETTING PLUGGED UP? The check engine light and traction light keep coming on until I use the stuff and then I'm good for a month.

 

Po430 doesn't mean the converter is plugged it means you have..

A) a fresh air leak into the exhaust diluting oxygen sensor readings - check for exhaust leaks

B) a lazy oxygen sensor - check oxygen sensor for responsiveness to rich/lean conditions

C) the catalyst has lost its ability to store oxygen and and combine it with HC - replace the converter assembly

Converters can get damaged from unburned fuel going down the exhaust. Any history of cylinder misfires? Bad spark plugs or ignition coils?

 

I have changed my spark plugs with plasma plugs
Buy Pulstar - Pulstar Spark Plugs
and coil packs with ripp coil packs
ripp tacoma coil pack - Search (bing.com)

This summer is when the cat was messing up, and so I tried to get it off, and almost did, but not quite. Couldn't even crack off the block, so I put all the nuts back on and torqued them to spec.
I changed my upper O2 sensors recently too, both sides, but not my lowers. I don't know if the lowers where the right ones or not when I put them in 2020, but they screwed in. Could that be the problem?
Remember, the passenger side is ok, it's just the driver's side that is giving me problems.

The cat smells really hot and stinks too, just wanted to add that.

How do I check for exhaust leaks?
The motor power care foam didn't expose any of that and I sprayed it up into the headers too, no leak. Maybe downstream around the coupler? UMH! Got me thinking now. One chance @ checking that this week in IL, 50 degrees.

 

I'm not familiar with Pulstar or Ripp, I would've used oem plugs and oem or denso coils.

Did you have misfires/misfire codes back when the p0430 showed up? Before the plugs and coils got replaced?

You can check for exhaust leaks by looking for soot and listening with a piece of tubing as a stethoscope. Partially blocking the exhaust outlet can help sometimes. There's other ways to check for exhaust leaks but they require more equipment like a scan tool and the ability to read fuel trims

 

Additionally, you can check for exhaust leaks if you have a shop vac by switching from suck to blow (SpaceBalls the comment) when you have the hose in the exhaust. Some soapy water spray on all the connections will bubble if there's an air leak. Even minor leaks could introduce enough air to throw off the sensor. Start by checking all the connection points forward of the Rear O2 Sensor.

-J

 

Gentlemen I will reread the post and try what you've said.
Thanks, Brian