2012 Nissan Pathfinder - cleaning up the cat

Accidentally grabbed a 5 gallon can of diesel fuel because I didn’t think I had enough gas to make it to the station. The vehicle ran but would bog down, backfire, smoke like crazy. Drove to shop and they figured it out and drained it. Runs great, however, check engine light stays on and keep reading catalytic converter. Garage checked and said it was showing that because of soot that is coating it but is running fine. They suggested running premium fuel and it may help. Will it, what can I do to clean it up? I want to sell it but hard to do with light on. Thanks so much

Premium fuel won’t do anything to help.
You MIGHT get lucky by driving on the interstate for several hours to clear the cat.


You might be surprised how cheap a new catalytic converter is from an independent muffler shop. Maybe $200-300 installed.

If you’re just looking to sell the vehicle soon, it might be an option.

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I would lose faith in a mechanic who recited that nonsense.

Ever since I was a child (and that is a LONG time), I have heard from an incredible number of uninformed people who believed that many auto maladies could be “cured” by the use of premium gas. To think that a mechanic would spout that type of nonsense is… disturbing.

Dump a bottle of Cataclean in the tank, and cross your fingers.




Thanks so much I’ll try it and running the roads for a couple hours. If that doesn’t work I’ll start searching for deals on replacement. You guys are the best!