Help with DTC code

[etc]

2000 Camry 2.2L

P0420 Catalyst efficiency below threshold

Is it one of the O2 sensors, if so, which one?

And where do I get a replacement (online?)

[Axel Kain]

02 sensors bad, or cat. is bad.

did you replace your cat recently?

[toyomoho]

The CAT monitoring system is stating the 02 sensors before and after the CAT have the same strength of signal. The CAT could be defective, open in short in 02 sensors or heated 02 sensors. Can’t say what part it is. The Toyota dealer should be able to determine the component quickly using their hand held scanner. An oscilloscope will also work.

http://oregonstate.edu/~tongt/camry

[csaxon]

You may have a bad converter. But, there are other conditions that can falsely set this code.
There can be no exhaust leaks. If there are fix them.
The heater circuit or the heating element in the sensor behind the converter has to be checked. The heater is used to get the oxygen sensor hot and functioning quickly to reduce exhaust emissions.
If the wiring to or the heating element itself is bad you can get a false converter code. So that part of the system must be diagnosed and repaired before the converter is deemed inefficient.

[zoni]

Originally Posted by csaxon

There can be no exhaust leaks. If there are fix them.

I like this one.... but if you are smart enough to get the codes read, and actually care about your car, you probably arent running around with a hole in your exhaust. If there is... it would more than likely be around the CAT. Your car is around the age where a CAT could start going bad...

[etc]

No, I didn't touch the cat, ever.

Where do I get a nice "hand held scanner" so I can trouble shoot this further? Or software for my laptop?

[zoni]

http://www.obd-codes.com/trouble_cod...old-bank-1.php

thats the only thing a scanner will tell you... the trouble code. and you already know it.

[Axel Kain]

thats what dealers are for....sorry to say guys, but dealers are becomming the only ones that can truely work on these coming cars, the future is gonna be expensive no matter what.

oh, and good luck, the dealer is truely the place to go for something like that, esp. for a car that's that new.

[zoni]

that new??? its a 2000. its still a 5sfe. its basically the same as the older ones...

[toyomoho]

This is one of those codes where you can either replace a bunch of parts or have the dealer do the analysis with the Toyota hand held diagnostic equipment. The can also do an exhaust gas analysis to see if the CAT is really working OK. If you know how to use an oscilloscope you can see the actually wave forms the sensors are putting out and determine if it is a sensor failure.

Most likely either the CAT is bad or the 02 (or A/F) sensors that monitor the CAT are bad or perhaps wiring.

I suggest you pay the dealer to diagnose the situation. If a CAT you can tell them you need to think about what will be a very high replacement cost. Then go get an aftermarket unit.

[etc]

Where can I buy this "Toyota hand held diagnostic equipment"?

Is it some kind of software program on the laptop that can take readings in real time as it's running? I've seen these, they seem to have way more capabilities than hand-held scanners.

Most likely either the CAT is bad or the 02 (or A/F) sensors that monitor the CAT are bad or perhaps wiring.

I don't feel any reduced power which I would think is a symptom of a bad cat?

Secondly, what is the A/F sensor?

[camryvibe]

Originally Posted by toyomoho

If you know how to use an oscilloscope you can see the actually wave forms the sensors are putting out and determine if it is a sensor failure.

I've got an old scope which should work ok as long as the frequency isn't too high. Is there a place to see what the waveform is supposed to look like?
Don't have this problem yet with our Camry but it's getting to the age where I expect it to become more likely.

[etc]

The heater circuit or the heating element in the sensor behind the converter has to be checked

Why not just replace the O2 sensor? It's almost at 80K and is probably due for replacement anyway, as they start to get "lazy" right around that mileage?

[ghettosled]

i had the same code come up on my car about a year ago. it was the cat for me, and there were no other signs (reduced power, egg smell, noise - nothing). i did also replace the second oxygen sensor just to be safe (plus the old one put up a very good fight in not wanting to come out). i got a new sensor at www.oxygensensors.com. cheap and quick.

[etc]

Thanks for reply. How do I confirm that it's really the cat?

I had tests run at Autozone with their sophisticated scanner which is how I got that P0420 Catalyst efficiency below threshold code.

Where do I get a replacement cat? Is it difficult to install?