Don't be in a rush to replace your "cats"

Along about 180,000 miles, our good ol' 2006 Toyota gave warning. The "check engine" light came on, and three different shops told us we needed to replace one or more catalytic converters.

Nope, not going to rush into that, we said. The cat replacement cost was close to what the car's trade-in value would be. So I started digging on the Internet.

What I learned was the PO430 code, usually interpreted as catalytic converter failure, can have a multitude of causes, and could be triggered by something as simple as a clogged air filter, dirty fuel injectors, or a bad sensor. So I picked up a new air filter, and a couple cans of Seafoam fuel additive (as suggested by an Internet post), and dumped a can each into the gas tank on consecutive fill ups.

The "check engine" light went off less than 500 miles later.

That was two years ago. And shortly thereafter, we retired the Sienna from my wife's high mileage daily use in favor of a new Honda Odyssey. But the Toyota seemed too good to practically give away for a couple grand. So we kept it as a knock-around vehicle for trips or tasks deemed too rough or dirty for the "new" Odyssey.

Last week, approaching 197,000 miles, the Sienna's "check engine" light popped on again. Sure enough, the cheap Harbor Freight diagnostic tool I bought last go-round showed the same error code. Another can of Seafoam was run through with another tank of gas, and I erased the codes.

Been a couple more hundred miles now, and the codes haven't come back.

The Internet is an especially valuable tool when troubleshooting problems on today's complex vehicles. As long as you know how to phrase your symptoms for a search engine, chances are you'll find others who have had the same issues, along with multiple suggestions on how to deal with them. Even if you're not mechanically inclined, you might find a YouTube video to lead you step-by-step through troubleshooting that otherwise might seem too complex to even attempt.

There's a time and a place to move forward on costly repairs or vehicle replacement.  But other times, when possible, it's best to check alternatives, and do some experimenting, before committing a pile of cash.