2001 Toyota Camry Catalytic converter
 

For the past few months, I've been battling the following problem. My
"check engine" light came on in my 2001 Toyota Camry (4 cylinder). The
code, P0420, indicates that the catalytic converter needs to be
replaced. Okay, the people at the muffler shop say that the front
converter -- the one in the exhaust manifold needs to be replaced. I
do that. The light comes on again. This time, it's the same code, so
I get the rear converter -- the one near the muffler -- replaced. The
next day, my check engine light comes on again. What's the problem
with this car?! I'm at my wit's end. I keep being told that it's the
friggin' converter, but it MUST be something else! Everybody says my
oxygen sensors "seem to be working okay". What else can it be? Is my
on-board-computer corrupted or something?!

HELP!

On 6 Mar 2005 09:01:47 -0800, "2confused" > wrote:

>For the past few months, I've been battling the following problem. My
>"check engine" light came on in my 2001 Toyota Camry (4 cylinder). The
>code, P0420, indicates that the catalytic converter needs to be
>replaced. Okay, the people at the muffler shop say that the front
>converter -- the one in the exhaust manifold needs to be replaced. I
>do that. The light comes on again. This time, it's the same code, so
>I get the rear converter -- the one near the muffler -- replaced. The
>next day, my check engine light comes on again. What's the problem
>with this car?! I'm at my wit's end. I keep being told that it's the
>friggin' converter, but it MUST be something else! Everybody says my
>oxygen sensors "seem to be working okay". What else can it be? Is my
>on-board-computer corrupted or something?!
>
>HELP!

I've never owned a Toyota, so take this with a large grain of salt:

The only way the engine computer knows anything about the catcon is by
looking at feedback from the O2 sensors. Period. Full Stop. End of
Program.

The frequency and amplitude of the S1 is compared to the frequency and
amplitude of the S2 and if the S2 is too close
e.g. normal is 127 cycles of S1 to 7 cycles of S2
if those numbers are too close together, a code is thrown *see above*

I would take a real good look at those O2 sensors. A real good look
on a dual-trace storage scope. Oh, you don't HAVE one. Well then, go
to somebody who knows what they are doing instead of just selling you
*stuff* which you don't need.

Lg

On 6 Mar 2005 09:01:47 -0800, "2confused" > wrote:

>For the past few months, I've been battling the following problem. My
>"check engine" light came on in my 2001 Toyota Camry (4 cylinder). The
>code, P0420, indicates that the catalytic converter needs to be
>replaced. Okay, the people at the muffler shop say that the front
>converter

snip...

There is an oxygen sensor before and after the converter. The
computer checks the converters efficiency by looking for a difference
between the two. No difference gives you a code that the converter
isn't working efficiently. I would suspect that one of your sensors
is not working properly and reading overly rich or lean. How many
miles on the vehicle? Original sensors?

Steve B.

The car has 103,000 miles and the original sensors.

On 6 Mar 2005 14:55:36 -0800, "2confused" > wrote:

>The car has 103,000 miles and the original sensors.

Sounds about right, mileage wise.

I think you should also look at your short term and long term fuel
trim numbers, but we'll leave that for another day.

Nothing against Toyotas, BTW. Just an outsider's observations.

Lg

There is a TSB regarding replacement of the cat AND reprogramming of the
engine control unit for some 01 and 02 camrys. Go to a toyota dealer with
your VIN and they will tell you if it is applicable to your car.

>The car has 103,000 miles and the original sensors.

Thats pretty good mileage for an oxygen sensor. I would replace the
back on first then the front if that doesn't solve the problem. Stay
away from Bosch. Stern knows who makes the good ones... Hopefully he
will speak up.

Steve B.

On Tue, 08 Mar 2005 00:15:47 GMT, Steve B. > wrote:

>>The car has 103,000 miles and the original sensors.
>
>Thats pretty good mileage for an oxygen sensor.

His sensor is dead. Kaput. He gave the voltages. dead. d e a d
No doubt, all his O2 sensors are kaput.
How much is it to replace them if he has 4? not counting labor,
probably $300 for parts.
YMMV

Is it worth it? How long will it take OP to recover his *investment*
?

> I would replace the
>back on first then the front if that doesn't solve the problem. Stay
>away from Bosch. Stern knows who makes the good ones... Hopefully he
>will speak up.
>
> Steve B.

On Mon, 07 Mar 2005 18:19:32 -0600, Lawrence Glickman
> wrote:

>On Tue, 08 Mar 2005 00:15:47 GMT, Steve B. > wrote:
>
>>>The car has 103,000 miles and the original sensors.
>>
>>Thats pretty good mileage for an oxygen sensor.
>
>His sensor is dead. Kaput. He gave the voltages. dead. d e a d
>No doubt, all his O2 sensors are kaput.
>How much is it to replace them if he has 4? not counting labor,
>probably $300 for parts.
>YMMV
>
>Is it worth it? How long will it take OP to recover his *investment*
>?
>
>> I would replace the
>>back on first then the front if that doesn't solve the problem. Stay
>>away from Bosch. Stern knows who makes the good ones... Hopefully he
>>will speak up.
>>
>> Steve B.

Sorry. Brain fart.
Wrong thread.

Lg