I have a 2004 Toyota Sienna, and the check engine light has come on. The code is saying that it's my Catalytic Converter. Would using high octane gas help with my situation?


You are taking about a PO420 Diagnostic code. I discussed this in the article. High Octane gasoline can help clear out the Catalytic Converter, and this has helped me, and people I know, avoid having to replace the unit. But it's no guarantee. If it's damaged enough, the check engine light will come back on again later.

It's a worthwhile thing to try since the cost of a tank of High Octane is much less than the price or replacement and labor. If it works, you might get a few more years out of it. I have.

Keep in mind, another thing that can be causing the OBD diagnostic code is a stuck sensor. If the light keeps coming back on with this code, then this should be considered too. I trustworthy mechanic should be able to determine this. But try the High Octane method, as I discussed in the article, before you start spending money on repairs.

Updated on April 9, 2018

Original Article:

Catalytic Converter: Avoid Unnecessary Repairs and Save Your Money
By Glenn Stok