Code P0420
Thread Starter
Racer
Joined: Dec 2013
Posts: 389
Likes: 30
Code P0420
I have a code P0420. What can I do besides replacing the catalytic converter?
Anyone try this?
Catalytic-System Clean | LIQUI MOLY (liqui-moly.com)
Anyone try this?
Catalytic-System Clean | LIQUI MOLY (liqui-moly.com)
Burning Brakes
Joined: Mar 2021
Posts: 889
Likes: 211
From: OH
I have a code P0420. What can I do besides replacing the catalytic converter?
Anyone try this?
Catalytic-System Clean | LIQUI MOLY (liqui-moly.com)
Anyone try this?
Catalytic-System Clean | LIQUI MOLY (liqui-moly.com)
https://acurazine.com/forums/4g-tl-2.../#post16857840
Intermediate
Joined: Dec 2006
Posts: 26
Likes: 3
From: Chandler, Az.
This is what I did.
I ended up changing out all 4 of my O2 sensors even though it was showing only 1 (Downstream rear. Can't remember which bank...sorry) of them was faulty. Eric the Car Guy has a pretty good video on Youtube about it. Sorry I don't have the link atm. Don't spend $$$ on assuming your cats are bad although 4 O2 sensors did cost over $200 from RockAuto. My TL is in damn good shape for an 04 as I keep it maintained and plan to keep it for life is why I changed out all 4 at 130k miles. GL.
Also I did use CataClean too before changing the O2 sensor and it didn't clear the P0420 code so that's why I looked deeper..
Also I did use CataClean too before changing the O2 sensor and it didn't clear the P0420 code so that's why I looked deeper..
Last edited by MaszTL; Dec 7, 2022 at 03:18 PM.
Racer
Joined: Jun 2019
Posts: 415
Likes: 74
I ended up changing out all 4 of my O2 sensors even though it was showing only 1 (Downstream rear. Can't remember which bank...sorry) of them was faulty. Eric the Car Guy has a pretty good video on Youtube about it. Sorry I don't have the link atm. Don't spend $$$ on assuming your cats are bad although 4 O2 sensors did cost over $200 from RockAuto. My TL is in damn good shape for an 04 as I keep it maintained and plan to keep it for life is why I changed out all 4 at 130k miles. GL.
Also I did use CataClean too before changing the O2 sensor and it didn't clear the P0420 code so that's why I looked deeper..
Also I did use CataClean too before changing the O2 sensor and it didn't clear the P0420 code so that's why I looked deeper..
Thread Starter
Racer
Joined: Dec 2013
Posts: 389
Likes: 30
If your catalytic converter has a minor issue, you might be able to fix it without replacing it. There are a few methods you can try.
- Fuel additives, like Cataclean, are one of the first and easiest methods to try for fixing a catalytic converter issue. Just add the product to your fuel tank and then drive your car for 15 minutes.
- These are especially useful if you use regular gasoline instead of premium varieties, as more expensive fuel already contains additives.
- You can also try using lacquer thinner. For this method, you’ll want to pour about one gallon of lacquer thinner into your half-full gas tank. Then, drive on the highway for around 150 mile
^^^This has to be quite possibly the stupidest thing I have ever seen.
Last edited by CenturionTL; Dec 8, 2022 at 01:34 PM.
Instructor
Joined: Sep 2020
Posts: 112
Likes: 27
From: Cali
Cat cleaning is tricky. In California, the street punks do you a favor by stealing your cat every couple of years. A friend in SF has lost 4 cats off her Prius this year alone. 50 state cats start at $1k, so there are lots of angry people. If you're in the 46 states, cats are cheap.
If you feel like cracking off those rusty bolts on your exhaust, that soap and water trick could work. Sure the Cataclean hurts your seals, but it's quick and easy. Just run it all through in one long drive and then get some fresh fuel in the lines. I've had several friends use it and they reported it got them another few years on a cat.
Some people claim "quenching" O2 sensors makes them last a few more years. Haven't tried it, but it makes sense.
Like they always say, Your Mileage May Vary (YMMV).
If you feel like cracking off those rusty bolts on your exhaust, that soap and water trick could work. Sure the Cataclean hurts your seals, but it's quick and easy. Just run it all through in one long drive and then get some fresh fuel in the lines. I've had several friends use it and they reported it got them another few years on a cat.
Some people claim "quenching" O2 sensors makes them last a few more years. Haven't tried it, but it makes sense.
Like they always say, Your Mileage May Vary (YMMV).
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