Catalytic converters and resale value

So, you start your car one morning and it sounds like a tractor. Or maybe you’ve seen the news stories about people crawling under cars in broad daylight.

What explains this phenomenon? In a word: catalytic converters.

You probably never think about this part of your car until you lose it. But this little piece of your exhaust system is a huge deal. It affects the air we breathe, how your car runs, and—here’s the kicker—how much money you can get when you decide to sell your car.

Let's break down what this thing is, why everyone seems to want it, and what it means for your wallet.

What exactly is a catalytic converter?

In simple terms, it’s a tiny pollution control device bolted to your exhaust system. Think of it as a mini science lab that cleans up your car’s messy exhaust gases before they puff out into the atmosphere. Here’s a video to help you locate your catalytic converter.

Inside its metal shell is a ceramic honeycomb. Super rare and valuable precious metals like platinum, palladium, and rhodium coat this honeycomb. These metals aren’t just for show; they act as catalysts. They trigger crucial chemical reactions while staying intact.

Here’s the basic chemistry magic trick it performs:

• It takes nasty stuff like hydrocarbon and carbon monoxide (which are bad for us) and converts them into less harmful carbon dioxide and water vapor.
• It also neutralizes nitrogen oxides, which are a primary component of smog.

This whole process is why we have cleaner air in cities today than we did decades ago. It’s a brilliant piece of engineering that’s required on every car in the United States thanks to rules set by the Environmental Protection Agency.

Why do thieves want your catalytic converter?

You’ve probably guessed it by now: those precious metals we just mentioned. They’re worth a ton of money.

• Rhodium can be worth over $15,000 per ounce.
• Palladium can be worth around $2,000 per ounce.

Your average catalytic converter only has a few grams of these metals, but that’s enough for a thief to make hundreds of dollars at a scrapyard. Some cars, like the Toyota Prius, have converters that are extra rich in these metals, making them a prime target. This is why catalytic converter theft has become such a huge problem.

A thief can slide under a car with a high clearance (like a truck or SUV), cut the converter loose with a power tool in under a minute, and be gone before anyone notices.

How does this all affect your car’s resale value?

This is where it gets real for anyone who plans to sell their car someday. Your catalytic converter is directly tied to your car’s value, and not having one, or having a bad one, is a massive red flag for any buyer.

Let’s look at the different scenarios:

Here's the bottom line: losing your converter tanks your car's value. Most people shopping for a used car aren’t mechanics. They see a “check engine” light or hear about a needed $2,000 repair and they run for the hills. Most buyers will avoid this complication.

And it’s not just about private sales. Over 30 states require regular emissions testing. If your car can’t pass because the converter is missing or broken, you can’t register it. That makes your car practically worthless to anyone who needs a legal, daily driver.

Can’t I just take the thing off?

Technically, your car will run without a catalytic converter. Your engine might even feel a tiny bit peppier because there’s less restriction in the exhaust system. But let’s be real: it’s a terrible idea.

First, it’s illegal. The Environmental Protection Agency has rules for the whole United States that make it illegal to remove a functioning converter. The fines are steep.

Second, your car will run poorly. Modern cars have oxygen sensors that monitor the exhaust.

When you remove the converter, you throw those sensors for a loop. This can make your car run poorly, hurt your gas mileage, and that annoying check engine light will never, ever turn off.

Finally, it’s just bad for the environment. Instead of clean carbon dioxide and water vapor, your car will be pumping out harmful fumes.

What are the signs of a bad catalytic converter?

What are the indicators of a failing converter? Watch for these signs:

• The Rotten Egg Smell: A sulfur smell from your exhaust is a classic sign the chemical reactions inside aren’t working right.
• You’ve Lost Your Get-Up-and-Go: A clogged converter chokes your engine, leading to sluggish acceleration.
• The Check Engine Light is On: This light can mean a thousand things, but it’s often the first sign of a converter or oxygen sensor issue.
• You Fail an Emissions Test: This is the most obvious sign that your pollution control system isn’t doing its job.

The easy way out: what to do if your converter is a problem

Let’s say the worst happens. Thieves stole your converter, or your mechanic just told you that you need a $2,000 replacement. You’re staring down a huge repair bill on a car you were hoping to sell.

Trying to sell a car privately without a converter is tough. Dealerships will offer you next to nothing for it. This is where a service like Peddle changes the game.

We specialize in buying cars “as-is.” That means exactly as they sit. No repairs needed.

• Missing catalytic converter? No problem.
• Check engine light permanently on? We've seen it.
• Failed your emissions test? We still want your car.

You can get an online offer in minutes, and we’ll come to you to pick up the car for free. It’s the simplest way to turn a car with a busted converter into cash without the headache of repairs or stressful negotiations.

So, protect that converter if you can with a shield or by parking carefully. But if it becomes a problem, know that you have an easy way out that protects your wallet and your peace of mind.