Scotty Kilmers' P0420 method

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Feb 25, 2009
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Location
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I'm going for it with his Lacquer thinner method. I just filled up this weekend and the code came up again yesterday (came on two weeks ago but I deleted it).

My question : if 1 gallon is ok for half tank, could I possibly use 2 gallons on a full tank? Or would this be exposing the rubber fuel lines to too much Naphtha/Toluene over the course of the tank?

For reference: It's a 200K Subaru that's ugly as sin but runs near perfect.

Thanks.
 
Are you attempting to get it to pass an inspection or emissions test? That being the case, I would think you need just enough to get the emissions monitors to run after clearing the code and hopefully the P0420 doesn't set.
 
I don't have first hand experience with your exact scenario, but would be concerned running a fair amount of that stuff through the fuel system.

Spark plug non-fouler an option?
 
In this video by Midwest F150, he used a bottle of Valvoline Restore and Protect Fuel System Cleaner (actually, he spilled some in the initial video) and the P0420 code went away, but later came back. He added another bottle in this video, and in a subsequent video, said the code went away again and had yet to come back. The car uses a quart of oil every 500 miles. I've been watching his trying to stem the flow to no avail, yet. He's not technical, but is trying hard to help his brother who owns the car.
 
In this video by Midwest F150, he used a bottle of Valvoline Restore and Protect Fuel System Cleaner (actually, he spilled some in the initial video) and the P0420 code went away, but later came back. He added another bottle in this video, and in a subsequent video, said the code went away again and had yet to come back. The car uses a quart of oil every 500 miles. I've been watching his trying to stem the flow to no avail, yet. He's not technical, but is trying hard to help his brother who owns the car.
Another shill post. Quart every 500 miles means proper diagnostics; not dumping chemicals in it.

Codes can come and go depending on driving conditions. My 2000 Jeep has a broken harness on one of the downstream O2 sensors (planning to replace soon). Sometimes CEL comes on for a day or two and then with continued highway driving it can go out. Clearly it needs fixed.

Don't assume random chemicals are fixing the problem. If you're just trying to pass emissions sometimes you can reset the light and drive it for 50+ miles and check to make sure there are no incompletes then get it inspected right away.
 
Another shill post. Quart every 500 miles means proper diagnostics; not dumping chemicals in it.
My belief is using a product made specifically for fuel system cleaning, Valvoline Restore and Protect Fuel System Cleaner, would be better than starting off using lacquer thinner.
 
My belief is using a product made specifically for fuel system cleaning, Valvoline Restore and Protect Fuel System Cleaner, would be better than starting off using lacquer thinner.
Valvoline Restore and Protect is the best! Disregard methodical emissions diagnostics that stuff is a scam from mechanics and the EPA; take advice from Mr. Kilmer :)
 
Wow! That is pretty brave of you to admit to the BITOG crowd, that you intend to follow the advice of Scotty Kilmer. Hopefully you have very thick skin.

Seriously though, why would you choose to follow his extremely questionable advice? Have you already tried the time proven method of using a couple treatments of fuel system cleaner to clear the code?

Oh, I just realized you are from Scotty's home state of Texas. Is there a little loyalty to a fellow Texas native going on here?
 
Wow! That is pretty brave of you to admit to the BITOG crowd, that you intend to follow the advice of Scotty Kilmer. Hopefully you have very thick skin.

Seriously though, why would you choose to follow his extremely questionable advice? Have you already tried to time proven method of using a couple treatments of fuel system cleaner to clear the code?
Played out in a picture

IMG_0287.webp
 
Some around here swear by running a certain amount of E85. I would do that before laquer thinner - you have no idea what cocktail mix is.

Cataclean might be worth a try. It might get you through emissions. A good long run on the highway helps also.
 
Don't listen to that clown. A proper cleaner for vehicles will often make the code clear temporarily if the cat is on it's last legs. To get through an emissions test you can also add a couple gallons of e85 to 1/4 tank of gas. Drive for a while to heat up the cat and go test. Fill up with regular fuel after the test. I've personally had success doing that with no damage done because new cats for my BMW were $4k+
 
Wow! That is pretty brave of you to admit to the BITOG crowd, that you intend to follow the advice of Scotty Kilmer. Hopefully you have very thick skin.

Seriously though, why would you choose to follow his extremely questionable advice? Have you already tried the time proven method of using a couple treatments of fuel system cleaner to clear the code?

Oh, I just realized you are from Scotty's home state of Texas. Is there a little loyalty to a fellow Texas native going on here?
He moved to Tennessee like 3 years ago.
 
What is lacquer thinner supposed to do? ...cleanse crud off the cat's reactive surfaces?
That's what they say and I'd imagine as it heats up may fool the sensors for a while, but I really couldn't say for sure.
 
Is it consuming a lot of oil?
Do you have an exhaust leak?
Are your O2 sensors getting a bit dodgy?
There’s so many questions, but I don’t think lacquer thinner is the answer.
 
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