What is a catalytic converter?
A catalytic converter is part of a vehicle’s exhaust system that “cleans” exhaust by converting harmful emissions into safer ones before being released. Without it, your car would emit far more pollutants and fail its annual inspection.
Types of catalytic converters
There are three types of catalytic converters currently on the road today:
- Two-way catalytic converters: These older converters work to break down two types of emissions — hydrocarbons (HC) and carbon monoxide (CO). After passing through the converter, these get released as carbon dioxide (CO2) and water (H2O).
- Three-way catalytic converters: Newer cars feature these components, which deal with nitrogen oxide (NO) in addition to HC and CO. After going through the conversion process, these get released as CO2, H2O, nitrogen (N2) and oxygen (O2).
- Diesel oxidation catalysts (DOC): Like two-ways, converters for diesel engines break down HC and CO. They can process NO — but not quite as effectively as three-way converters can.
How much does it cost to replace a catalytic converter?
According to RepairPal data, the average replacement cost for a catalytic converter ranges from $936 (for a 2019 Ford F-150) to $5,460 (for a 2019 Dodge Charger).
This aligns with the results of our most recent study, which showed a range of $933 to $4,414. We received estimates from five different mechanics across the country — the estimates below are based on three different car models.
| Vehicle | Average parts cost | Average labor cost | Average total cost |
|---|---|---|---|
| 2017 Honda Civic | $4,108 (93% of total cost) | $306 (7% of total cost) | $4,414 |
| 2017 Ford F-150 | $757 (81%) | $176 (19%) | $933 |
| 2019 BMW 740i | $720 (31%) | $1,589 (69%) | $2,309 |
Of our sample vehicles, the Honda Civic, which is generally affordable in terms of repair and maintenance, had by far the highest catalytic converter replacement costs. Meanwhile, the BMW 740i had the lowest average parts cost but a much higher labor cost. The Ford F-150, one of the most popular vehicles in America, had the lowest average replacement costs by far.
Some vehicles, like Toyota and Honda, have a much more expensive catalytic converter than brands like Ford."
Additional costs in catalytic converter replacement
Replacing a catalytic converter often comes with extra charges beyond the part and labor. Here are the most common “hidden” or easily overlooked costs to watch for:
- Diagnostic fees: Before replacement, shops typically run scans or perform manual inspections to confirm the converter is the true issue — not an O2 sensor, misfire or fuel-system problem. Expect $50 to $150 depending on the shop’s labor rate.
- Taxes: Depending on your state, sales tax on parts can add 5% to 10% to the total bill, especially if the converter is an expensive OEM unit.
- Shop fees: Many repair shops charge environmental or supply fees, usually $15 to $50, to cover disposal, rags, chemicals and equipment use.
- Hardware and gaskets: Rusted bolts, clamps and exhaust gaskets often need replacement during catalytic-converter work. These add-ons are typically $20 to $100 but can be more if cutting and welding are required.
- Oxygen sensor replacement: O2 sensors often seize in place or fail around the same time as the converter. Replacing one typically adds $150 to $300 per sensor (part and labor). Some cars have multiple sensors, increasing the cost.
Because these expenses vary by vehicle age, rust level and the shop’s diagnostic process, it’s smart to ask for a line-item estimate upfront. Request a written quote that includes parts, labor, diagnostics, shop fees, tax, and any potential add-ons such as sensors or hardware. This helps you compare shops accurately and avoids unexpected charges when the final bill arrives.
OEM vs. aftermarket catalytic converter cost comparison
Replacing a catalytic converter can be expensive, and choosing between an OEM or aftermarket unit affects both cost and performance. Understanding the differences in price, warranty, compliance, fit and longevity can help you make the best choice.
| Feature | OEM converter | Aftermarket converter |
|---|---|---|
| Price | Expensive. Often $800–$2,500+ for part alone. | Budget-friendly. Often $200 to $800 for a quality direct-fit unit. |
| Warranty / support | Factory-grade warranty and strong manufacturer support. | Warranty varies widely. Good brands may offer multiyear warranties; budget units may have little to none. |
| Emissions compliance / legal | Guaranteed compliance with emissions regulations for your make/model. Ideal for strict states. | Compliance depends on brand and certification (EPA-approved or state‑certified). Risk of failed inspection if uncertified. |
| Fit & compatibility | Exact match. Bolt-on fit, correct sensors and flow dynamics. | Fit may vary. Direct-fit models often work well; “universal” units may require welding/modifications. |
| Longevity & performance | High-grade materials, thicker catalyst substrate, generally lasts 100,000+ miles. | Lifespan varies. Quality units can be solid, but cheaper ones tend to wear out faster or degrade emissions performance over time. |
Choose an OEM catalytic converter if:
- You want guaranteed emissions compliance, especially important in states with strict laws.
- Your vehicle is relatively new, under warranty or you plan to keep it for many years.
- You prefer reliable performance and long-term durability, even at higher upfront cost.
Choose a quality aftermarket catalytic converter if:
- Your vehicle is older or has high mileage, so the lower upfront cost makes more sense.
- Budget constraints are a concern, or you just need a functional replacement after theft or damage.
- You carefully select a reputable aftermarket brand that meets emissions standards (EPA or state-certified).
How much does it cost to repair a catalytic converter?
When people talk about repairing a catalytic converter, they’re usually referring to the process of cleaning it, which can technically be done with $20 to $30 of cleaning supplies. However, most mechanics advise against even attempting to “repair” your cat yourself — and few are likely to take the job on.
“Cleaning a cat may seem like a good idea to save a few bucks, but most of the time it ends up costing about as much to replace it with a new one,” Jay Jindal of Jindal-Andre Automotive Services in Washington, D.C., explained. “Granted, some vehicles, like Toyota and Honda, have a much more expensive catalytic converter than brands like Ford. It’s best to weigh out the options.”
Cleaning a cat may seem like a good idea to save a few bucks, but most of the time it ends up costing about as much to replace it with a new one.”
If your catalytic converter is damaged beyond just clogging, repair is generally not practical.
Even if you can improve your catalytic converter’s functions by cleaning it, it isn’t likely to save you much money in the long term. Most cats only get significantly dirty after many years (around 10 to 15, in most cases) of use, and they’re likely to need replacing soon after this point, if not at the same time. After you spend the time and money to clean your converter, it probably won’t be long until you need to fork over the money to replace it.
Plus, it’s hard to predict whether a cleaning will actually save you money since cat repairs are billed by the hour at local labor rates. Getting an estimate ahead of time is difficult because a shop doesn’t know how dirty your catalytic converter is until it’s out of your vehicle.
As a result, you may have to spend more money figuring out why your catalytic converter clogged up in the first place.
» MORE: Most expensive car repairs
What if you have a warranty or insurance?
Under some circumstances, your insurance company or warranty provider may cover the cost of replacing your catalytic converter. Below, we’ve outlined two scenarios in which you may not have to pay as much — or at all — for a new cat.
- If your catalytic converter was stolen, you’ll want to check with your car insurance provider to see if you’re covered. Comprehensive car insurance should cover the cost of a catalytic converter replacement in this case. Just keep in mind that you may still need to pay your deductible, and some comprehensive policies come with high out-of-pocket costs.
- If your catalytic converter failed and your vehicle is under warranty, you may not need to pay to have it repaired or replaced. The Environmental Protection Agency (EPA) mandates that automakers provide special warranties for emissions components, including catalytic converters. Under these warranties, major emissions components are covered for eight years or 80,000 miles, whichever happens first.
» MORE: Car warranty vs. car insurance
Extended warranty coverage
The catalytic converter is often covered under a vehicle’s factory warranty. That’s usually not the case for extended warranties.
If your vehicle hasn’t been maintained properly, your warranty coverage will likely be denied.
However, an extended warranty can still be helpful in the event of a failed catalytic converter. While these warranties don’t cover the parts themselves, many cover mechanical issues that result in catalytic converter failure.
For example, a blown head gasket can allow coolant to burn off in your engine, and that coolant can gunk up the catalytic converter. An extended warranty may not cover the cat, but it will help you fix that pesky leaking head gasket to stop the issue from recurring.
A reviewer from Ohio felt that their extended warranty was still worth it even after they had to pay out of pocket for their catalytic converter replacement: “After not receiving a discount on my catalytic converter failure, I was hesitant when my mechanic submitted the list of items that needed repaired on my Jeep. … CarShield covered items that I didn't expect them to cover, including the rental car, front and back brakes, water pump assembly with everything that was associated, and saved me thousands of dollars.”
» MORE: Best extended car warranties
FAQ
DIY vs. professional installation cost comparison?
Replacing a catalytic converter yourself can save money on labor. Do-it-yourself (DIY) costs usually include just the part ($300 to $1,200 for aftermarket, $1,000 to $3,500+ for OEM) plus tools and supplies. However, DIY carries significant risks: improper installation can cause exhaust leaks, O2-sensor damage or check-engine lights, potentially leading to more costly repairs.
Professional installation typically costs $100 to $300 in labor (in addition to the part) but ensures proper fitment, correct torque and safe handling of exhaust components. Pros also handle O2 sensor replacement, diagnostics and disposal of the old catalytic converter, reducing risk of errors or fines.
What can happen to my car if I don’t repair my catalytic converter?
According to the EPA, the catalytic converter is your car's most important pollution control device. If this fails and you don’t repair it, several things can go wrong. For starters, you won’t pass any emissions testing, which is a requirement in some states. You will also find that you are spending more on gas, and eventually, if left untreated, it will cause significant engine and exhaust system damage.
Is replacing a catalytic converter worth it?
It’s worth replacing a catalytic converter in the financial sense. Not having one can do costly damage to your engine and exhaust system as well as significantly lower your gas mileage. It may also be difficult to sell your vehicle or get a reasonable price for it without one. In addition, you need a catalytic converter to pass your annual vehicle inspection and remain in compliance with the law.
How does a catalytic converter work?
If you open up a catalytic converter, you’ll see what looks like a dense, honeycomb structure. This structure is made from heat-resistant ceramic, and it’s there to provide more surface area for exhaust gases to flow over. This honeycomb grid is also laced with precious metals, typically from the platinum family.
Each metal functions in a specific way:
Reduction catalysts, like rhodium and platinum, react with nitrogen oxide by removing oxygen and breaking the molecular bonds into nitrogen and oxygen, which are harmless.
Oxidation catalysts, like palladium and platinum, change carbon monoxide into carbon dioxide by adding oxygen.
Once this happens, the resulting exhaust gases are moved out through the tailpipe into the air.
What should you do if your catalytic converter is stolen?
If your catalytic converter has been stolen, you should get it replaced as soon as possible. Not only is driving without a catalytic converter loud — it’s also often illegal.
Your best bet to replace the catalytic converter is to visit a respectable muffler shop or automotive repair facility. You can go to the dealer as well, but you may pay quite a bit more money.
What are the signs of a faulty catalytic converter?
If your catalytic converter is still in place but you suspect that it’s not working properly, there are several signs you can look for to see if it’s faulty:
- Poor fuel efficiency: If a catalytic converter gets clogged, it can cause a backup of airflow coming out of the engine. This will lead to a drop in efficiency, which you’ll see at the pump.
- Check engine light: One of the purposes of your vehicle's electronic control unit (ECU) is to monitor your vehicle’s systems. The ECU measures air-to-fuel ratios regularly, and if this ratio is out of whack, it will trigger a “check engine” light. Although this is not a guarantee the catalytic converter is at fault, certain engine fault codes may indicate a problem with the catalytic converter.
- Rotten egg smell: If a cat is clogged up or becomes damaged, the smell of rotten eggs can waft into your car. This happens due to the partial conversion of nasty pollutants, which manifests as sulfur dioxide.
- Poor performance: Due to a lack of exhaust gas movement, a clogged catalytic converter can have a major effect on performance. Since the exhaust gases must escape, the back pressure may cause your engine to stall or completely shut off.
- Failed emissions tests: Most people find out their catalytic converter has bit the dust when the vehicle fails an emissions test due to high levels of pollutants being emitted.
How long does it take to replace a catalytic converter?
Replacing a catalytic converter is a relatively straightforward process for mechanics. It should take about two hours to complete.
Do extended car warranties cover catalytic converters?
Most extended car warranties do not cover defective catalytic converters. However, they may cover the issue that caused the converter to fail.
How can I tell if my catalytic converter has been stolen?
One of the telltale signs that your catalytic converter has been stolen is that your car is suddenly quite a bit noisier than normal. Because catalytic converters are placed before mufflers in most exhaust systems, your car will make significantly more noise now that there’s a gap in your exhaust system.
If you suspect your catalytic converter is gone, pop your head under your car near the front seats and look for any missing sections in your exhaust system.
Article sources
ConsumerAffairs writers primarily rely on government data, industry experts and original research from other reputable publications to inform their work. Specific sources for this article include:
- RepairPal, “Catalytic Converter Replacement Cost Estimate.” Accessed Dec. 7, 2025.
- CarVira, “Understanding Catalytic Converters: Complete U.S. Maintenance and Replacement Guide” Accessed Dec. 7, 2025.
