>>> >>>
>>>>
>>>>> >>>>>
>>>>> [SNIP]
>>>>>>
>>>>>>Sorry, you're out of luck on the emissions warranty. If you want to >>>>>>invest
>>>>>>in a volt/ohm meter, you can check out the O2 sensors yourself and see >>>>>>if
>>>>>>they are working properly or not.
>>>>>
>>>>> What should the readings be?
>>>>> --
>>>>> Jay (remove dashes for legal email address)
>>>>
>>>>Here is a pretty good explanation of how O2 sensors work and what the
>>>>voltages should be:
>>>>
formatting link
>>
>>> Thanks -- good reference!
>>> --
>>> Jay (remove dashes for legal email address)
>>
>> You're welcome!
>
> P0420 is usually reliable (sorry.)
>
> O2 Sensors have to respond reliably and consistently to their tests to set > this.
I'm not sure what you mean by a "reliable' code. If you check the factory service manual, you will see the the first step in diagnosing this code is to check the O2 sensors first.
> cyl 1, 2, 3 => B1
> cyl 4, 5, 6 => B2
>
The OP's car has an in-line configuration - there is no bank 2.
Look for aftermarket cat. ... they exist.