DTC P0420 -Shocking the cat?
09-13-2009, 08:16 AM
#1
DTC P0420 -Shocking the cat? No, not plugging Tabby into 110 volts. This concerns a fairly new cat that is once again throwing P0420, which is a converter efficiency fault.
I read a thread somewhere else that they were successful by doing the following (not an f-body):
Run the fuel down as much as possible
Pour in a 20 oz. bottle of Chevron Techron Concentrate Plus Fuel System Cleaner (enough for 20 gallons of fuel)
Put in 8 gallons of Chevron hi-test (93 octane, IIRC)
Run the fuel down as much as possible
Fill tank with high-test
Their theory was that the concentrated cleaner "washed" the crud off the cat and cleaned it out. They claimed it worked for them; of course, this is the web I am speaking of, so the b/s filter is on high.
I read a thread somewhere else that they were successful by doing the following (not an f-body):
Run the fuel down as much as possible
Pour in a 20 oz. bottle of Chevron Techron Concentrate Plus Fuel System Cleaner (enough for 20 gallons of fuel)
Put in 8 gallons of Chevron hi-test (93 octane, IIRC)
Run the fuel down as much as possible
Fill tank with high-test
Their theory was that the concentrated cleaner "washed" the crud off the cat and cleaned it out. They claimed it worked for them; of course, this is the web I am speaking of, so the b/s filter is on high.
09-13-2009, 10:13 AM
#2
^ Not sure on additives.
This preocedure may have cleaned the injectors some - just enough to get this guy under the SES light threshold. I suppose you could try it because the cost is minimal, but I doubt it.
A bad cat usually has part or all of the substrate deformed, which is non repairable.
But your cat is fairly new. Some of the performance cats do not clean the exhaust to the liking of the downstream O2 sensor. I assume you have matching cats, and the code is for the driver's side only.
I don't think I'm helping much on this one, but just throwing a few ideas around.
This preocedure may have cleaned the injectors some - just enough to get this guy under the SES light threshold. I suppose you could try it because the cost is minimal, but I doubt it.
A bad cat usually has part or all of the substrate deformed, which is non repairable.
But your cat is fairly new. Some of the performance cats do not clean the exhaust to the liking of the downstream O2 sensor. I assume you have matching cats, and the code is for the driver's side only.
I don't think I'm helping much on this one, but just throwing a few ideas around.
09-13-2009, 10:58 AM
#3
Sorry, I had intended to state this is on my g/f daily driver, an 03 Saturn L200. It is a replacement cat from Meineke, and another shop claims it is just a low quality cat. Of course, they want $$ to replace it with yet another aftermarket cat which may be just as low quality.
I did a real-time scan and datalog using Autotap, and the rear O2 is dancing around, which OBD-II.com claims will set the code.
I also noticed that it was pulling timing occasionally, which OBD-II claims could be a culprit. But I'll have to dig deeper on that one, since it is a completely stock vehicle and the log run was a very sedate run.
I did a real-time scan and datalog using Autotap, and the rear O2 is dancing around, which OBD-II.com claims will set the code.
I also noticed that it was pulling timing occasionally, which OBD-II claims could be a culprit. But I'll have to dig deeper on that one, since it is a completely stock vehicle and the log run was a very sedate run.
09-13-2009, 12:47 PM
#5
I agree on the rear O2, it should be fairly smooth, and it is not. I was hoping that the cleaner would be effective, but I just don't see how that could be. There is even a cleaner that O'Rielly's is selling that they "guarantee will let your car pass emissions or your money back". What's up with that?
There's also a product called Cataclean that they claim will clean the cat, but they want $25 for a bottle. Sounds like snake oil to me.
The warranty is up at Meineke, not sure I would go back there anyhow.
Thanks for the assist.
There's also a product called Cataclean that they claim will clean the cat, but they want $25 for a bottle. Sounds like snake oil to me.
The warranty is up at Meineke, not sure I would go back there anyhow.
Thanks for the assist.
