Marc 85Z28

iTrader: (8)

Are you high? WTF is that supposed to mean. If you didn't need to be taught how the system works, you wouldn't question my statement about the impossibility of a catalyst monitor setting a catalyst inefficiency DTC. Clearly, you don't grasp how the system works.

JaYZeig

iTrader: (11)

lol...ok

jaysan

iTrader: (8)

Ahhhhhh ******* code came back . I drove the car out of the dealership and 2 days later the code came back . What should I do ?

rnl35thss

iTrader: (14)

[QUOTE=Marc 85Z28;15560237]1. It is IMPOSSIBLE for an O2 sensor (catalyst monitor in this case) to set a catalyst inefficiency DTC.


A slow upstream O2 will, normally will have some BXS1 codes along with it, but not always.

OP- I would suggest scanning and looking at upstream O2 activity, if its only flagging B2, see how B1 and B2 compare. They should be very active.

jaysan

iTrader: (8)

Would a fuel treatment help To remove carbon build up ? Could that set that code off ? I will be taking my car to a tuner , hopefully he can give a better code reader .

BullittZ28

Fuel treatment shouldn't do anything at all IMO.

RPM WS6

iTrader: (3)

He can just delete the code, and then you're done with it. As long as the front O2 sensors are functioning properly, that's all that matters. The only reason why the rear O2s would be a concern is if you have to pass an OBD emissions scan, in which case a custom tune or O2 sims could take care of that.

It's great if you can get this fixed for free (by the dealer, for those still under warranty), but I wouldn't spend a bunch of money to chase down the problem since it's just an emissions code and can be deleted/ignored (again, assuming the front O2s are working properly).

Marc 85Z28

iTrader: (8)

No, it won't. If the PCM detects slow repsonse on one of the sensors as compared to another, it would set a DTC. Furthermore, a PCM WILL NOT set a catalyst inefficiency DTC if it detects slow repsonse on either of the 2 sensors. Slow response CANNOT trigger a catalyst inefficiency DTC. See my post above about researching how this system operates.

Marc 85Z28

iTrader: (8)

Take it back to the dealer! Same DTC? You say the car was "fixed". What did they actually do?

jaysan

iTrader: (8)

They put 2 new cats on . I am going to get the codes deleted . I don't want to **** with it any more lol

rnl35thss

iTrader: (14)

CIRCUIT DESCRIPTION
In order to maintain reasonably low emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx), the engine controls system uses a 3-way catalytic convener. The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO in the exhaust gas. This reaction converts these chemicals into harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting the NOx to nitrogen. The powertrain control module (PCM) monitors this process using Bank 1 HO2S # 2. Bank 1 HO2S # 2, located in the exhaust stream past the 3-way catalytic converter, produces an output signal which indicates the oxygen storage capacity of the catalyst. This determines the catalyst's ability to effectively convert the exhaust emissions. If the catalyst is functioning correctly, the Bank 1 HO2S # 2 signal will be far less active than the signal produced by Bank 1 HO2S # 1. This indicates that the 3-way catalytic converters oxygen storage capacity is below an acceptable threshold.

When the Conditions for Running this DTC are met, the following conditions occur:

The PCM captures the current rear HO2S rich-to-lean status.
The Air/Fuel ratio transitions from rich to lean, or from lean to rich, depending on the capture rear HO2S rich-to-lean status.
The Air/Fuel ratio transitions a second time opposite the first Air/Fuel ratio transition.
The PCM captures the response time of the front and rear heated oxygen sensors when the Air/Fuel ratio transitions occurred. The response time is the time during which the HO2S goes from below 300 mV to above 600 mV , and from 600 mV to below 300 mV .
The PCM measures the time for the rear HO2S voltage to cross a reference rich-to-lean threshold, minus the time for the front HO2S voltage to cross the same rich-to-lean threshold. The time difference from the front and rear HO2S is the oxygen storage capacity of the catalyst. This DTC sets if the time exceeds a predetermined threshold.


^Above is from service info. Marc- I am by no means saying that the best way to take care of a P0430 is to slap upstream O2s on it. What I am saying is that it can. I've seen it before. I would also be asking the dealer why they didn't fix it. If we disagree then I can agree to disagree. OP- tune away!

RPM WS6

iTrader: (3)

That's the best bet, IMO. Cat inefficiency is only a problem if you need to pass a sniffer test, and tuning/O2 sims can take care of any scan tests that you might need to pass.

Marc 85Z28

iTrader: (8)

That threshold they speak of is the switch ratio, or index ratio. You can actually monitor a converter's efficiency by graphing the 2 sensors and comparing (if you know what you're looking at). Comprehensive use of Mode 6 component and test IDs can do the same. In order for the catalyst sensor to set this DTC, it would have to fail so that it's readings were still inline with the oxygen sensor, yet slower in response time. A silicated sensor's slow switch time is NOT the same as a slow response time as compared to the oxygen sensor.