Code P0420. Bad Catalytic or O2 sensor?
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Code P0420. Bad Catalytic or O2 sensor?
Hello
I recently bought a 98 SC400 and its been great so far.
When I bought it it had the check engine on, which turned out to be the pre-cat O2 sensors which I replaced both.
The light went out for a day or two and came back on. Now its throwing code P0420 (reduced catalyst efficiency, bank 1)
I did some search here and on the internet but couldn't find a definitive conclusion about it being the cat or the O2 sensor.
I'm leaning towards bad cat because they make a lot of noise when I shut the car off. Its a clicking sound most of you have probably heard but I think in my car is a little too much noise.
Even in 10 minutes short drives it will make the clicking noise once I shot it down.
Any tips from someone who has had this problem before? Any way to find out if in fact my catalytic converter is bad?
Would a muffler shop be able to weld a aftermarket one like magnaflow in its place or does it have to me OEM?
Thanks for the help
I recently bought a 98 SC400 and its been great so far.
When I bought it it had the check engine on, which turned out to be the pre-cat O2 sensors which I replaced both.
The light went out for a day or two and came back on. Now its throwing code P0420 (reduced catalyst efficiency, bank 1)
I did some search here and on the internet but couldn't find a definitive conclusion about it being the cat or the O2 sensor.
I'm leaning towards bad cat because they make a lot of noise when I shut the car off. Its a clicking sound most of you have probably heard but I think in my car is a little too much noise.
Even in 10 minutes short drives it will make the clicking noise once I shot it down.
Any tips from someone who has had this problem before? Any way to find out if in fact my catalytic converter is bad?
Would a muffler shop be able to weld a aftermarket one like magnaflow in its place or does it have to me OEM?
Thanks for the help
#2
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Since most codes are universal now between all manufacturers, P0420 is usually a cat converter code.. See if some other members or posts show what they used, for an aftermarket cat converter.. Much cheaper than factory, hopefully a good aftermarket part.
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Good info in this thread. It gives tips on what to look for in voltage on the o2 sensor before you replace the cat, as well as a discussion on this exact issue with high flow cats instead of oem.
https://www.clublexus.com/forums/per...er-cat-o2.html
If you end up concluding (or replacing everything) and the issue is not the o2 sensor or cat. Then the fun begins
https://www.clublexus.com/forums/per...er-cat-o2.html
If you end up concluding (or replacing everything) and the issue is not the o2 sensor or cat. Then the fun begins
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