P0430 CAT Below Efficiency, Bank2
 

The car runs good, no problems. Spark plugs are old, 150,000 miles and 16
years (1997 vehicle).

I decide to change the plugs. No troubles BEFORE I begin.

When I am done, the engine runs poorly, severe -- or at least notable --
misfire. I drive for a day or two -- probably about 50 miles or less --
until the check engine light comes on. I pull codes, a single cylinder
misfire. No big deal, I discover the plug wire not seated well on the plug,
easy to cure.

Engine instantly runs better -- misfire is gone.

Now I am driving around with the scan tool connected just to be sure that
the things I feel in the seat of my pants don't turn into a fresh round of
engine codes. I don't feel much, and no misfire reports. Life is good.

Hold your horses, life is not so good.

I have a Pending Code, P0430 CATALYST BELOW EFFICIENCY BANK2. The check
engine light has not come on yet, but if the problem is true, then it should
come on in a few more drive cycles.

My question is, if I have a misfire will the resulting raw fuel damage the
CAT or the post-CAT sensor? I was not aware that a misfire could take a CAT
out. The misfire that I had is in Bank2, so there is a correlation between
the misfire and the new code.

Of course, there is a strong possibility that the plugs I installed are not
the right ones -- just because the parts guy says that the catalog calls for
them does not mean they are right. After putting the plugs in, I went to the
dealership to get the factory plugs and plug wires -- $230 for plugs and
wires from the dealership, ouch! -- but have not installed them because the
engine now feels just like it did before I started working on it. (Curing
the misfire code fixed the poor operation, entirely, so I'm in no hurry to
open the hood again. It was very difficult to reach the plugs, and if the
engine runs then I don't want to do the job over again.)

So, my question is if I damaged my CAT or if it is merely a coincidence that
I have a P0430 Code in pending status?

P0430 CAT Below Efficiency, Bank2
 

Jeff Strickland wrote:
> Spark plugs are old, 150,000 miles
> and 16 years (1997 vehicle).
>
> I decide to change the plugs. ...
>
> When I am done, the engine runs poorly, ... I discover the plug wire
> not seated well on the plug, easy to cure.
>
> Engine instantly runs better -- misfire is gone.
>
> Now I am driving around with the scan tool connected ...
>
> I have a Pending Code, P0430 CATALYST BELOW EFFICIENCY BANK2...
>
> So, my question is if I damaged my CAT or if it is merely a
> coincidence that I have a P0430 Code in pending status?

raw fuel will certainly damage a catalytic converter, but not
necessarily in just a few miles or days. reset the PCM with the scan
tool and drive it long distances for a few days and see if a P0430 comes
up again. And I might even do that one more time again.

The parameters to set a "cat-efficiency" code are unlikely to occur from
a bad sensor, just a bad cat-con. And the cat-con is just as likely
worn out from age and not changing the plugs 75,000 miles ago, as from
the recent "whoops" with the plug wire.

I am speaking purely of OBDII operational engine mangement theory, not
of any case-specific "known issue" on a 1997 BMW/Toyota What-ever-mobile.
GW

P0430 CAT Below Efficiency, Bank2
 

Whilst you were not firing one cylinder lots of unburnt fuel will have got
into the cat and 'polluted' it.

Now that all six are firing again, my guess is that a couple of long runs
will warm the cat up, provide exhaust with low levels of hydrocarbon and
allow catalytic conversion of hydrocarbons in the cat' restoring it to
health.


"Jeff Strickland" > wrote in message
...
> The car runs good, no problems. Spark plugs are old, 150,000 miles and 16
> years (1997 vehicle).
>
> I decide to change the plugs. No troubles BEFORE I begin.
>
> When I am done, the engine runs poorly, severe -- or at least notable --
> misfire. I drive for a day or two -- probably about 50 miles or less --
> until the check engine light comes on. I pull codes, a single cylinder
> misfire. No big deal, I discover the plug wire not seated well on the
> plug, easy to cure.
>
> Engine instantly runs better -- misfire is gone.
>
> Now I am driving around with the scan tool connected just to be sure that
> the things I feel in the seat of my pants don't turn into a fresh round of
> engine codes. I don't feel much, and no misfire reports. Life is good.
>
> Hold your horses, life is not so good.
>
> I have a Pending Code, P0430 CATALYST BELOW EFFICIENCY BANK2. The check
> engine light has not come on yet, but if the problem is true, then it
> should come on in a few more drive cycles.
>
> My question is, if I have a misfire will the resulting raw fuel damage the
> CAT or the post-CAT sensor? I was not aware that a misfire could take a
> CAT out. The misfire that I had is in Bank2, so there is a correlation
> between the misfire and the new code.
>
> Of course, there is a strong possibility that the plugs I installed are
> not the right ones -- just because the parts guy says that the catalog
> calls for them does not mean they are right. After putting the plugs in, I
> went to the dealership to get the factory plugs and plug wires -- $230 for
> plugs and wires from the dealership, ouch! -- but have not installed them
> because the engine now feels just like it did before I started working on
> it. (Curing the misfire code fixed the poor operation, entirely, so I'm in
> no hurry to open the hood again. It was very difficult to reach the plugs,
> and if the engine runs then I don't want to do the job over again.)
>
> So, my question is if I damaged my CAT or if it is merely a coincidence
> that I have a P0430 Code in pending status?

P0430 CAT Below Efficiency, Bank2
 

"Geoff Welsh" > wrote in message
...
> Jeff Strickland wrote:
>> Spark plugs are old, 150,000 miles
>> and 16 years (1997 vehicle).
>>
>> I decide to change the plugs. ...
>>
>> When I am done, the engine runs poorly, ... I discover the plug wire
>> not seated well on the plug, easy to cure.
>>
>> Engine instantly runs better -- misfire is gone.
>>
>> Now I am driving around with the scan tool connected ...
>>
>> I have a Pending Code, P0430 CATALYST BELOW EFFICIENCY BANK2...
>>
>> So, my question is if I damaged my CAT or if it is merely a
>> coincidence that I have a P0430 Code in pending status?
>
> raw fuel will certainly damage a catalytic converter, but not
> necessarily in just a few miles or days. reset the PCM with the scan
> tool and drive it long distances for a few days and see if a P0430 comes
> up again. And I might even do that one more time again.
>
> The parameters to set a "cat-efficiency" code are unlikely to occur from a
> bad sensor, just a bad cat-con. And the cat-con is just as likely worn
> out from age and not changing the plugs 75,000 miles ago, as from the
> recent "whoops" with the plug wire.
>
> I am speaking purely of OBDII operational engine mangement theory, not of
> any case-specific "known issue" on a 1997 BMW/Toyota What-ever-mobile.
> GW


I have reset the P0430, and the code has returned. Several short trips,
that's my normal driving profile. I sometimes will drive for 30-ish miles
one-way, but generally my trips are shorter.

I would not have thought that I could damage the CAT in the time it took to
have the P0306 MISFIRE CYLINDER 6 move from the Pending column to Active.

I'm okay with theory of operation over practical application.

P0430 CAT Below Efficiency, Bank2
 

"R. Mark Clayton" > wrote in message
...
> Whilst you were not firing one cylinder lots of unburnt fuel will have got
> into the cat and 'polluted' it.
>
> Now that all six are firing again, my guess is that a couple of long runs
> will warm the cat up, provide exhaust with low levels of hydrocarbon and
> allow catalytic conversion of hydrocarbons in the cat' restoring it to
> health.
>
>

You think I can "clean" the CAT? That's a comforting thought. I'm all about
saving money, and the wait-and-see method of repair seems logical given the
cost of repair.

P0430 CAT Below Efficiency, Bank2
 

Jeff Strickland wrote:
>
> "Geoff Welsh" > wrote in message
> ...
>> Jeff Strickland wrote:
>>> Spark plugs are old, 150,000 miles
>>> and 16 years (1997 vehicle).
>>>
>>> I decide to change the plugs. ...
>>>
>>> When I am done, the engine runs poorly, ... I discover the plug wire
>>> not seated well on the plug, easy to cure.
>>>
>>> Engine instantly runs better -- misfire is gone.
>>>
>>> Now I am driving around with the scan tool connected ...
>>>
>>> I have a Pending Code, P0430 CATALYST BELOW EFFICIENCY BANK2...
>>>
>>> So, my question is if I damaged my CAT or if it is merely a
>>> coincidence that I have a P0430 Code in pending status?
>>
>> raw fuel will certainly damage a catalytic converter, but not
>> necessarily in just a few miles or days. reset the PCM with the scan
>> tool and drive it long distances for a few days and see if a P0430
>> comes up again. And I might even do that one more time again.
>>
>> The parameters to set a "cat-efficiency" code are unlikely to occur
>> from a bad sensor, just a bad cat-con. And the cat-con is just as
>> likely worn out from age and not changing the plugs 75,000 miles ago,
>> as from the recent "whoops" with the plug wire.
>>
>> I am speaking purely of OBDII operational engine mangement theory, not
>> of any case-specific "known issue" on a 1997 BMW/Toyota What-ever-mobile.
>> GW
>
>
> I have reset the P0430, and the code has returned. Several short trips,
> that's my normal driving profile. I sometimes will drive for 30-ish
> miles one-way, but generally my trips are shorter.
>
> I would not have thought that I could damage the CAT in the time it took
> to have the P0306 MISFIRE CYLINDER 6 move from the Pending column to
> Active.
>
> I'm okay with theory of operation over practical application.
>
>
as the other post mentions, you need one good long trip.
GW

P0430 CAT Below Efficiency, Bank2
 

"Jeff Strickland" > wrote in message
...
>
> "R. Mark Clayton" > wrote in message
> ...
>> Whilst you were not firing one cylinder lots of unburnt fuel will have
>> got into the cat and 'polluted' it.
>>
>> Now that all six are firing again, my guess is that a couple of long runs
>> will warm the cat up, provide exhaust with low levels of hydrocarbon and
>> allow catalytic conversion of hydrocarbons in the cat' restoring it to
>> health.
>>
>>
>
> You think I can "clean" the CAT? That's a comforting thought. I'm all
> about saving money, and the wait-and-see method of repair seems logical
> given the cost of repair.
>
>

That depends on whether the catalyst has been inhibited (by the condensation
of hydrocarbons) or poisoned.

See http://en.wikipedia.org/wiki/Catalysis

I think the latter unlikely BMW's web site boasts "The system uses a special
set of parameters in the engine's warming-up phase in order to help the
catalytic converter reach its ideal operating temperature more quickly,
lowering emissions..." for double Vanos engines.

A good run will also help in removing oil and / or deposits in the
mis-firing cylinder.