Lacquer thinner fixed my P0420 catalyst efficiency problem

[FireFox31]

Adding lacquer thinner to my gas fixed my P0420 catalyst efficiency problem. 1.5 years and 25k miles later, the problem has not returned. People have speculated about the possible harm this can cause, so here's how it worked for me.

Starting in Nov 2013, my 2000 V70 began getting the P0420 code for catalyst system efficiency below threshold. When I reset it, the code would always return a short while later.

I dug around the forum and found reference to this YouTube video:
http://www.youtube.com/watch?v=5icTmYItwiE

I also found this post describing an attempt to use lacquer thinner:
https://www.matthewsvolvosite.com/forums ... 58#p242358

In May 2014 at 215k miles, I followed the above instructions and added a gallon of lacquer thinner to ten gallons of gas. I immediately drove 400 miles to drain the tank, not wanting the lacquer thinner to corrode anything by sitting in the gas tank too long. I filled the tank again, then drove another 400 miles just a few days later, getting rid of any remaining lacquer thinner that may have been in the tank.

One month and 2000 miles later, the P0420 code stopped appearing. Four months later, I passed inspection with no emissions problems.

Now it's 1.5 years and 25k miles later. The P0420 code has not returned and I've experienced no ill effects from having used the lacquer thinner.

My one recommendation is: When planning to mix a tank with lacquer thinner, start with an empty tank and add five gallons of gas, then one gallon of thinner, then five gallons of gas. This should help mix everything together well. Then immediately drive the gas tank empty and fill up again.

I hope this helps.

[Alberto1985]

Sounds like a nice fix! Cheap enough too! Does it clean out the injectors? I'd think so no?

[rspi]

You got 400 miles on 10 gallons of gas? Awesome!