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Discussion Starter · #1 ·
I need a little help here. I'm getting a P0430, but it's not consistent. I went to the library and looked up the diagnostic information for a P0430 in Mitchell. For good measure, I looked at the information for a P0420 as well. Under "conditions for setting DTC" for a P0420, one thing it mentions is TPS must be below 1.7%. This isn't mentioned under P0430, though one might expect the conditions for a P0430 to be the same. Can anyone confirm that a P0430 can only be set when TPS is low? It could explain why the code doesn't show up consistently for me.
 

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This is what I found. It doesn't mention the TPS.

Catalyst System Efficiency Below Threshold (Bank 2)

Basically this means that the [FONT=Verdana,sans-serif][FONT=Verdana,sans-serif]oxygen [/FONT][/FONT]downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.


A code P0430 may mean that one or more of the following has happened:
  • The catalytic converter is no longer functioning properly
  • An oxygen sensor is not reading (functioning) properly
  • There is an exhaust leak
Possible Solutions

First, inspect for[FONT=Verdana,sans-serif][FONT=Verdana,sans-serif]exhaust[/FONT][/FONT] leaks.
Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen [FONT=Verdana,sans-serif][FONT=Verdana,sans-serif]O2 [/FONT][/FONT] while you're at it.
 

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This is what I found. It doesn't mention the TPS.

Catalyst System Efficiency Below Threshold (Bank 2)

Basically this means that the [FONT=Verdana,sans-serif][FONT=Verdana,sans-serif]oxygen [/FONT][/FONT]downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.


A code P0430 may mean that one or more of the following has happened:
  • The catalytic converter is no longer functioning properly
  • An oxygen sensor is not reading (functioning) properly
  • There is an exhaust leak
Possible Solutions

First, inspect for[FONT=Verdana,sans-serif][FONT=Verdana,sans-serif]exhaust[/FONT][/FONT] leaks.
Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen [FONT=Verdana,sans-serif][FONT=Verdana,sans-serif]O2 [/FONT][/FONT] while you're at it.

What is the working voltage range for the O2 sensor? The 99 is tripping this code now.

I was just resetting the CIL-- no emissions test in my area, but now the engine is running rougher than usual.

How many O2 sensors are there? Are there two upstream and two downstream for a total of four?
 

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Discussion Starter · #4 ·
O2 sensors generate a voltage between 0 (high O2 content-lean) and 1 (low O2 content - rich) Volt.

And you are correct, there are 4 O2 sensors.
 

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O2 sensor R&R

How hard is it to remove the four O2 sensors? I might as well do all of them at once. Can I do it with the truck on ramps or do I have to drop the exhaust like I had to do on my BMW? Any recommended brands to use or brands to stay away from? I was thinking about using Bosch sensors...

Thanks for the help!!

Joe
 

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Discussion Starter · #6 ·
O2 sensors aren't too hard. You shouldn't have to drop the exhaust or anything like that.
 

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Thanks for the info!
 
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