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How much does it cost to replace a catalytic converter?

How much does it cost to replace a catalytic converter?

Replacing your catalytic converter can be a costly endeavour. In many cases, the replacement component itself isn’t the only expense.

Once your catalytic converter stops working (or is removed), you’ll be using more fuel – and potentially, causing significant damage elsewhere. Leaving this issue unchecked could land you with an eye-watering repair bill!

In this guide, we’ll cover typical replacement costs for a catalytic converter – and explain why a replacement is so expensive. We’ll also list the telltale signs that you need a new catalytic converter – and share some tips for saving money when it comes to replacement.

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What is a catalytic converter - and why is it important?

The catalytic converter is arguably the most important part of the emissions system. Its job is to break down toxic pollutants into less harmful (or completely harmless) ones through a series of chemical reactions.

For example, it reduces nitrogen oxides (NOx) into nitrogen gas (part of the air we breathe) - and changes hydrocarbons and carbon monoxide (CO) into water and carbon dioxide (CO₂). It then expels them into the environment from your exhaust. In short, the catalytic converter makes emissions less harmful before they are released into the environment, which helps to keep the air clean.

The UK has strict regulations regarding vehicle emissions as part of its commitment to achieving net zero emissions by 2050. These regulations include a combination of European Commission directives, nationwide UK Government policies, and regional measures such as the Ultra Low Emission Zone (ULEZ). If your car doesn’t comply with these requirements, you could be fined.

You’ll also automatically fail your MOT test if your car’s emissions exceed the legal limits. This could easily happen if your catalytic converter is broken or blocked - and can’t convert the toxic gases as it’s meant to.

How much does it cost to replace a catalytic converter in the UK?

The cost of replacing a catalytic converter can vary significantly depending on factors such as:

  • The make and model of your car.
  • The availability of the required part.
  • Where you get the work done.

This isn’t a quick job; you’ll typically need to factor in 2-4 hours’ labour, which includes removing the old catalytic converter and replacing it with a new one. You’ll usually pay between £150 and £900 (including labour) - although costs can be higher in some circumstances.

Here are some ballpark costs for different car types:

  • City cars and small hatchbacks: £150 to £250
  • Saloons and estate cars: £300 to £400
  • High-end and sports cars: £500 to £1000 (or more)

Why are catalytic converters so expensive?

Catalytic converters are expensive because they contain rare, precious metals, including palladium, rhodium, and platinum, which are the catalysts for the chemical reactions that convert the pollutants.

Prices for these metals fluctuate - but can be anywhere between £30 and £600 a gram. The installation also adds to the overall cost. It’s a complex job that requires someone with considerable mechanical experience and specialist tools, which translates to higher labour rates.

How can I tell if my catalytic converter needs replacing?

Here are some of the telltale signs that your catalytic converter needs replacing:

  • Reduced engine performance or acceleration.

  • Increased fuel consumption.

  • Dark smoke coming from your exhaust.

  • A rattling sound coming from the exhaust system.

  • A rotten egg smell.

  • Your engine warning light comes on.

If you notice any of these signs, take your car to a mechanic for inspection at the earliest opportunity.

Even if you’re unsure of the issue, it’s best to get a professional opinion. This will help you avoid more severe problems (and larger repair bills) further down the road.

You should also keep up with your servicing and maintenance schedule to avoid catalytic converter problems.

Can I reduce the cost of replacing a catalytic converter?

Whilst catalytic converter replacement is a relatively pricey job, there are certain steps you can take to minimise expenses:

  • Keep up with maintenance

    The best way to keep costs down is to take good care of your catalytic converter. Be mindful of the warning signs we covered earlier – and take your car to a mechanic as soon as you notice any of them.

    If you’re proactive, your mechanic may be able to repair (rather than replace) your catalytic converter. For example, they may simply patch a rust hole rather than replace the entire converter.

    You should also follow best practices such as using premium fuel, regularly having your exhaust system cleaned out – and going for long drives to ensure air circulates throughout the system.

  • Deter thieves

    Sadly, many drivers need catalytic converter replacement after having theirs stolen.

    Catalytic converters are frequently targeted by thieves due to the precious metals they contain. The number of catalytic converter thefts reported in the UK rose from 10,049 in 2013 to 27,195 in 2023 – marking a rise of 170%. A skilled thief can steal one in under a minute – and sell it for a good price at a scrapyard or via an online marketplace.

    However, there are steps you can take to deter prospective thieves, including:

    • Parking in secure places, such as a garage, patrolled car park, or somewhere that will prevent easy access (e.g. against a wall, on level ground, and/or surrounded by other cars).
    • You can also attach a specialist lock or alarm to your catalytic converter. Whilst this might not deter every would-be thief, it should give many second thoughts.

  • Get a variety of quotes

    If all else fails and you do need to replace your catalytic converter, you should obtain a variety of quotes from local garages. This should help you find the best possible deal and service for your catalytic converter replacement.

    If the quotes are near or above your car’s value, you may be wondering, “Is it time to sell my car?” At a minimum, you should assess whether it’s best to repair or sell your car.

    Unsure of your car’s market value? Use our free car valuation tool to get a quote in less than 30 seconds.

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