Save your money…In Mexico, P0420 is not an issue. It’s something to be ignored…
Not if you are required to pass smog verification. Fortunately, I am not. Not yet. They have discussed making import cars by retirees be verified, but not yet.
My area is one with smog verification for local cars. I am told for $50 USD all cars pass.
However, this is a Texas car, and eventually I will have to take it back, where it is required to have state inspection. They do not verify smog in McAllen, I can’t even find a shop to measure smog output. It was suggested I take it to Houston if I wanted to know how good it was on smog.
But, I am told there is a problem on state inspection, not sure if that is state wide. But, you are, or are not, it’s not clear, allowed one readiness failure whatever that means.
So, eventually it will have to be fixed.
More Googling. Still most comments are hypothetical, what I call guesses, how bad it is, and very few who have actually tried it, and they virtually all say it worked. Sigh.
I did find a lot of info on adding 2 ounces of acetone for each 10 gallons of gasoline, Supposedly increases miles unless gas has ethanol in it. Only one person said it cleaned his catalytic converter. And, a Dave Narby said he took a fuel pump apart and put the plastic parts in an acetone mixture twice as strong as the plan, and it didn’t harm them that badly over a long period of time. I do not think I will try acetone.
I do agree there is on rush on this, until September if/when I go back to Texas.