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Discussion Starter · #1 ·
I've had my check engine light scanned twice with the same problem of the catalytic converters missing. I had them clear it and it came back. I'm not too sure how to check and if they are missing how can I go about preventing the light from being on? I've ran gumout through my fuel tank in the last week and it hasn't done anything for me yet. Not sure what the problem is, or how to solve it. Any advice PLEASE HELP!!!
 

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Sorry to give you a non-answer but posting the actual codes along with the engine size might help others better understand the problem. When I read the phrase "catalytic converters missing" I am thinking there will be a big gap in the exhaust where the cat(s) used to be, and I doubt this will be the case as it would be easy to spot and the fix would be relatively obvious.

If the codes are for the catalytic converter being outside efficiency tolerance, I would think you have two main choices: -
  • Replace the failing catalytic converter (clearly the right thing to do)
  • Fool the emissions system by installing a spark plug non fouler on the secondary O2 sensor (may get you into trouble if discovered depending on local laws, environmentally inconsiderate, etc)
With the actual codes there might be other options / info.
Hope this helps
 

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BOOMER: I think your 2nd fix is more likely to fix that problem. If the ECM knows that a sensor is missing or not registering some codes, it will give an error code. any sensors missing from the "LOOP" will cause a bad read to the ECM.
 

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Discussion Starter · #4 ·
Sorry to give you a non-answer but posting the actual codes along with the engine size might help others better understand the problem. When I read the phrase "catalytic converters missing" I am thinking there will be a big gap in the exhaust where the cat(s) used to be, and I doubt this will be the case as it would be easy to spot and the fix would be relatively obvious.

If the codes are for the catalytic converter being outside efficiency tolerance, I would think you have two main choices: -
  • Replace the failing catalytic converter (clearly the right thing to do)
  • Fool the emissions system by installing a spark plug non fouler on the secondary O2 sensor (may get you into trouble if discovered depending on local laws, environmentally inconsiderate, etc)
With the actual codes there might be other options / info.
Hope this helps
The code my engine is throwing is P0420. Catalyst system low efficiency.
 

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Oxygen sensors in the exhaust don't last forever, recomended replace them at 100k miles. An older UPSTREAM O2 sensor that is failing will set this code. BTDT with a number of my own vehicles over ythe years.
 

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Discussion Starter · #8 ·
WELLLL.....NO cats and nowhere for the sensors to read from. NO fix without the system being correct.
Do you think having my exhaust guy put an o2 sensor would be able to fix my problem? The previous owner stripped the cat and just straight piped it i guess.
 

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Discussion Starter · #9 ·
Sorry to give you a non-answer but posting the actual codes along with the engine size might help others better understand the problem. When I read the phrase "catalytic converters missing" I am thinking there will be a big gap in the exhaust where the cat(s) used to be, and I doubt this will be the case as it would be easy to spot and the fix would be relatively obvious.

If the codes are for the catalytic converter being outside efficiency tolerance, I would think you have two main choices: -
  • Replace the failing catalytic converter (clearly the right thing to do)
  • Fool the emissions system by installing a spark plug non fouler on the secondary O2 sensor (may get you into trouble if discovered depending on local laws, environmentally inconsiderate, etc)
With the actual codes there might be other options / info.
Hope this helps
Code is P0420, would I be able to use your second tip and kinda fool the system? I could probably have my exhaust guy put an o2 sensor on my exhaust so it can read something.
 

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I would guess so, but have not tried it. The idea of the non foulers is to take the second (after the cat) sensor out of the exhaust stream. The first sensor is important for your fuel trims, the second is really only looking at the CAT efficiency as best as I understand it. Might be worth simply connecting an O2 sensor and see if that is enough to trick the system. There is probably also a way to simply feed the expected signal into the O2 connector, but that is beyond my capabilities.
 

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Discussion Starter · #11 ·
I would guess so, but have not tried it. The idea of the non foulers is to take the second (after the cat) sensor out of the exhaust stream. The first sensor is important for your fuel trims, the second is really only looking at the CAT efficiency as best as I understand it. Might be worth simply connecting an O2 sensor and see if that is enough to trick the system. There is probably also a way to simply feed the expected signal into the O2 connector, but that is beyond my capabilities.
Honestly, I have no idea how to do this. Is there any where you can point me for help on how to?
 

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Po420 is also for the Evap system, exhaust system leak and many other issue can cause it according to my scanner. It also says clogged cat. Obviously you don't have that issue.
 
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