From: tuco bonno on

i recently purchased for my wife a used 2003 4-cyl Camry, a/t, 125000
miles, from a toyota dealer. Nice car. After a couple weeks, the
check-engine light came on. I got out my Actron OBD II code scanner,
which i used to retrieve a P0420 DTC. I researched that DTC on the
internet and found out it is a "catalytic converter not performing to
spec" issue. I erased the code, and it has not returned in the month
since then. I dropped by the toyota dealer to discuss the issue w/ a
service tech, who told me that altho i could replace the catalytic
converter myself, i would still need to bring it by to them so that
they can "recalibrate the computer" after the new catalytic converter
has been installed. Back in the 60s and 70s, i had A LOT of
experience working on VW Bugs, rebuilding Bug engines, even once
rebuilt a VW bug standard transmission. So i like to think i know a
little bit about auto mechanics. But back then, VW Bugs did not have
catalytic converters, much less onboard computers. So i need to know:
on MODERN cars, do you need to recalibrate the onboard computer
whenever you replace the catalytic converter? or is this something
particular to Toyotas? I have both the Chilton AND the Haynes shop
manuals for this car, and neither one of them mentions any such
requirement. One further note: I found a TSB for this car on the
internet, Toyota TSB EG024-04, relative the onboard computer and P0420
DTCs, but the tech at the dealar told me it does not apply to *my*
engine b/c it was built after the Production Change Effective VIN (and
that jives w/ what i concluded).
From: dsi1 on
On 12/21/2009 5:08 AM, tuco bonno wrote:
>
> i recently purchased for my wife a used 2003 4-cyl Camry, a/t, 125000
> miles, from a toyota dealer. Nice car. After a couple weeks, the
> check-engine light came on. I got out my Actron OBD II code scanner,
> which i used to retrieve a P0420 DTC. I researched that DTC on the
> internet and found out it is a "catalytic converter not performing to
> spec" issue. I erased the code, and it has not returned in the month
> since then. I dropped by the toyota dealer to discuss the issue w/ a
> service tech, who told me that altho i could replace the catalytic
> converter myself, i would still need to bring it by to them so that
> they can "recalibrate the computer" after the new catalytic converter
> has been installed. Back in the 60s and 70s, i had A LOT of
> experience working on VW Bugs, rebuilding Bug engines, even once
> rebuilt a VW bug standard transmission. So i like to think i know a
> little bit about auto mechanics. But back then, VW Bugs did not have
> catalytic converters, much less onboard computers. So i need to know:
> on MODERN cars, do you need to recalibrate the onboard computer
> whenever you replace the catalytic converter? or is this something
> particular to Toyotas? I have both the Chilton AND the Haynes shop
> manuals for this car, and neither one of them mentions any such
> requirement. One further note: I found a TSB for this car on the
> internet, Toyota TSB EG024-04, relative the onboard computer and P0420
> DTCs, but the tech at the dealar told me it does not apply to *my*
> engine b/c it was built after the Production Change Effective VIN (and
> that jives w/ what i concluded).

Replace it yourself and don't worry about it unless the light comes back
on. Come to think of it, I wouldn't replace it unless it was causing
problems.

My old VW Rabbit had a neat service procedure for the converter if they
tended to pose restriction problems. This consisted of removing the
converter and bashing in the ceramic element with a broomstick handle
and knocking all the fragments out and replacing the empty shell. My
guess is that the car would then breath a little easier and as an added
bonus, have a slightly more throaty exhaust note. Oh boy! :-)