P0430 - which sensor to replace?

[tx4runnerag]

I'm getting a P0430 on our '04 4Runner (1GR-FE). From what I've read, it sounds like IF this is a bad sensor and not a bad catalytic converter, it's the one AFTER the cat - is that correct?

Is there an easy/quick way to test the O2 sensor to determine if that's the problem?

Also, from what I've read I believe bank 2 is the driver's (left, if sitting in the vehicle) side - is that correct?

 

[04runnerS4]

P0430 is a bank2 catalyst efficiency code. When a downstream/post cat O2 sensor signal is alternating from rich to lean fast, the cat is less efficient.

 

[Eastcoastrunner]

i got this code the other day. I believe it's the right side, and of course, I had an aftermarket header put on because Toyota can't sell anything for the 4runner for under a grand (major parts). Reset it with my obd scanner.
history on mine...both o2's on that side are within 1.5 yrs of age, new and toyota brand.
Quite frankly I am sick of my 4runner.
Suspension starts leaking, dealer says it's going to be $1500 a side to replace the xreas. I buy toyota springs and bilstein shocks.
Frozen calipers all day long
ticking due to cracked manifold...$1700 to replace each side at dealer
wheel bearings are making noise now
those are the major things, i have more to share LOL
Terrible on fuel to boot
Selling this thing after the winter. Done and done.

 

[tx4runnerag]

P0430 is a bank2 catalyst efficiency code. When a downstream/post cat O2 sensor signal is alternating from rich to lean fast, the cat is less efficient.

Is there an easy way to determine if the problem is the cat or a faulty sensor?