01 Sequoia with p0430 code

I just need some advice.

My 01 Sequoia has 122,000 mi on it. It has a check engine light on and
the code is a p0430 - no others. Now, from what I am reading it seems
almost certain to be a bad catalytic converter, but how can one be
sure? The local Toyota dealer will diagnose for $89, but I worry their
tech will plug it all in, see the code and just default to a bad cat.
At a cost of $1300 (not available aftermarket) just for the part,
though, that would be a hugely expensive default if it weren't truly
bad.

Any ideas on what I can do prior to taking it to the dealer?

Kevin

On 30 Aug 2005 17:02:07 -0700, "Kevin Jarrard" <kjarrard@gmail.com>
wrote:

>I just need some advice.
>
>My 01 Sequoia has 122,000 mi on it. It has a check engine light on and
>the code is a p0430 - no others. Now, from what I am reading it seems
>almost certain to be a bad catalytic converter, but how can one be
>sure? The local Toyota dealer will diagnose for $89, but I worry their
>tech will plug it all in, see the code and just default to a bad cat.
>At a cost of $1300 (not available aftermarket) just for the part,
>though, that would be a hugely expensive default if it weren't truly
>bad.
>
>Any ideas on what I can do prior to taking it to the dealer?
>
>Kevin


YOu can take it to an Auto Zone, if there's one around you. The last
time my check engine light came on they read the code and told me what
the problem was at no charge. I've heard others say the same of Auto
Zone.

Skip

P0430 Catalyst System Efficiency Below Threshold (Bank 2)

The ECM compares the waveform of the oxygen sensor located before the
catalyst with the waveform of the oxygen sensor located after the catalyst
to determine whether or not catalyst performance has deteriorated. Air-fuel
ratio feedback compensation keeps the waveform of the oxygen sensor before
the catalyst repeatedly changing back and forth from rich to lean. If the
catalyst is functioning normally, the waveform of the oxygen sensor after
the catalyst switches back and forth between rich and lean much more slowly
than the waveform of the oxygen sensor before the catalyst. But when both
waveform change at a similar rate, it indicates that catalyst performance
has deteriorated.

Detectiong Condition:
After engine and catalyst are warmed up, and while vehicle is driven within
set vehicle and engine speed range, waveform of heated oxygen sensors have
same amplitude (2 trip detection logic)

Trouble Area:
Gas leakage on exhaust system
Heated oxygen sensor
Three-way catalytic converter

Check gas leakage on exhaust system. NG Repair or replace.
OK- Check heated oxygen sensor (bank 1, 2 sensor 1) NG Repair or replace.
OK-Replace three-way catalytic converter.




"Kevin Jarrard" <kjarrard@gmail.com> wrote in message
news:1125446527.305264.305560@g44g2000cwa.googlegr oups.com...
>I just need some advice.
>
> My 01 Sequoia has 122,000 mi on it. It has a check engine light on and
> the code is a p0430 - no others. Now, from what I am reading it seems
> almost certain to be a bad catalytic converter, but how can one be
> sure? The local Toyota dealer will diagnose for $89, but I worry their
> tech will plug it all in, see the code and just default to a bad cat.
> At a cost of $1300 (not available aftermarket) just for the part,
> though, that would be a hugely expensive default if it weren't truly
> bad.
>
> Any ideas on what I can do prior to taking it to the dealer?
>
> Kevin
>

Good suggestion. Also make sure you do a tune up if not done recently.
Either the converter is bad or the cylinders are dumping too much
unburned gas, overwhelming the converter.

This is usually a code showing the symptom and not the cause.

Now is there a bad batch of converters for this truck?

Kevin Jarrard wrote:
> I just need some advice.
>
> My 01 Sequoia has 122,000 mi on it. It has a check engine light on and
> the code is a p0430 - no others. Now, from what I am reading it seems
> almost certain to be a bad catalytic converter, but how can one be
> sure? The local Toyota dealer will diagnose for $89, but I worry their
> tech will plug it all in, see the code and just default to a bad cat.
> At a cost of $1300 (not available aftermarket) just for the part,
> though, that would be a hugely expensive default if it weren't truly
> bad.
>
> Any ideas on what I can do prior to taking it to the dealer?
>
> Kevin
>
Check with a local muffler shop about welding the necessary fittings
on an aftermarket generic cat so it fits your truck. My S&S headers
include aftermarket cats, and they work well.

Try adding 3 oz. of acetone per 10 gallons of gas when you fuel. It
might work. Give it several tanks to clean things up. You also
might try running FP60 (http://www.lubecontrol.com/fuel.htm) for
several tankfuls. It it more than pays for itself in fuel savings,
stick with it. Don't be surprised if your engine runs rough before
it runs smooth while cleaning the combustion chamber. When carbon
deposits are partly removed, the remaining deposits may have rough
edges that upset the smooth flame propgation front.


Ken

Thank you for the run down. This helps direct my efforts, though I
need a little more help

1) Is there a good way for me to check the exhaust system for leeks at
home? I would guess a shop uses some sort of probe with a sensor, but
how can a shade tree mechanic do the same thing? Also, would a leak
that caused this issue have to be in a particular area (between the o2
sensors) or could it be anywhere from the exhaust manifold down?

2) How do I check the O2 sensor? I have an obdii connector for the car
(that's how I pulled the code in the first place) and have been playing
with some frewware obdii software, but I'm not certain I'm getting what
I need. I'm guessing I need to watch the voltage levels on the
appropriate sensor and make sure the max and min's are within operating
range? If the sensor were bad, though, wouldn't that through another
system code?

3) I don't know that the plugs have ever been changed in this vehicle
as we bought it new. I will take care of that, but could poor ignition
cause this error without causing another code to occur?

4) I don't understand how an exhaust leak could cause this problem.
Could somebody explain that?

5) Can other measures be looked at to better focus in on the problem?
Long or short term fuel trim ratios?


Thanks,
Kevin

Good idea no matter what, but I don't quite understand it in this
context. If the fuel cylinders are dumping an excess of unburned fuel
into the exhaust system, wouldn't the upstream o2 sensor sense this
then feedback this info so timing or fuel distribution would be
adjusted to try to overcome the problem? I would think this would
either "fix" the issue or result in a poor running vehicle due to
overcompensation.

Thanks,
Kevin

[BadChicken]

have the dealer run a system check on the bank 2 sensor 2 and check the voltage pattern of the sensor at 2000 rpm for 60 seconds or so. It should be relatively flat but if its jumping around, you need a cat.