Piston Slap: Golf Seeking New Friend, Must Love Cats

TTAC Commentator AKM writes:

I own a 2002 VW Golf with 115,000 miles and want to sell it since we’re moving overseas (probably will buy another VW there). Belt changed at 100,000 miles, brakes at 110,000, tires at 100,000. The car is in great overall condition.

However, the engine light is on, simply because the catalytic converter is running below efficiency. According to the mechanic, the only solution is to replace it with an OEM part (i.e. VW-branded) as others might be below the specs required and thus activate the engine light immediately. It’s a $700 part, plus labor.

Do you think it’s worth repairing it before selling it, or selling it as is while explaining the problem? Edmunds gives me an approximate value of $4500, more likely $4000 with the issue not fixed. But what really matters is what buyers will think.

I have another option, which is to buy the part online. The only converter I find for my car is the “Eastern” model, generally at $275. Do you know if it’s the same converter as the original, and can I install it myself, or would it mess up the oxygen sensor?

Sajeev replies:

I would repair it, because receipts for work inspire confidence. You aren’t selling a car: you are selling a car with pre-packaged convenience and peace of mind. But I am a little surprised the converter failed. Are you sure it isn’t a bad rear oxygen sensor instead? These heated O2 Sensors usually lose their luster at this mileage.

And with that, Paranoia Alert! I’ve seen some jackasses overcharge people for a replacement cat (not the one that goes meow) when it was a bad rear O2 sensor or vacuum/EGR problem in reality. An O2 sensor is roughly $50 each. But there’s more cheddar in that fix when you charge for a cat that looks just like your current part.

Would you be able to tell the difference between your VW cat and a replacement VW part? But let’s assume your mechanic has scruples and uses them on a regular basis.

Aftermarket cats are hit or miss, yet they usually misbehave months/years after installation. At that price, I’d go with Eastern, and they claim a five-year warranty, too. Should make the new owner happy, and it has an OEM-ish design that won’t trigger the VW’s electronics like a universal aftermarket unit. Probably. Talk to your mechanic and see if he’s willing to order (and return if necessary) an aftermarket cat.

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