To ensure a better experience, we save information regarding your visit to Read more

The best how-to guide to your car

How to Replace the Catalytic Converter

25 June 2015, 10:38
Exhaust Most car owners will never need to replace their catalytic converter during the lifetime of their vehicle. They are built to last and are not exposed to the same levels of wear and tear as moving parts of the car. But a build-up of rust over time and significant knocks to the underside of the car could cause irreparable damage to your catalytic converter and mean that you would have to replace it completely. You could save yourself some serious cash by installing the new catalytic converter yourself.
Get up to 3 quotes for exhaust repair now Here is a step by step guide of how to do so should you ever need to.


Make sure the car is parked on level ground and jack up all 4 wheels so that it is completely off the floor.


Make sure that the exhaust has had time to cool down. Don’t attempt to replace the catalytic converter straight after the car has been running.


Find the catalytic converter. It should not be difficult to locate, it will look like a box in the middle of the exhaust pipe system underneath the car. Exhaust Repairs


Inspect the converter to see whether it is welded or bolted to the car. If it has been welded in position then you may not be able to remove it yourself. If you have access to the correct tools and are confident removing the converter then you will be able to continue with the replacement yourself. If not, you will need to take your car to a garage to have a professional look at it.


Take the oxygen sensor off the main catalytic converter. Some models of car might have more than one oxygen sensor.


Even if your converter is bolted rather than welded, it can still be difficult to remove. Rust can affect the bolts, making them extremely hard to remove. Penetrating oil could be your solution.


Every catalytic converter is slightly different, even though they all do the same job. This means that the installation process may differ from one converter to the next. If the new converter you have purchased comes with instructions, make sure that you read these through several times and follow them carefully.


New catalytic converters often come with small gaskets which fit inside the pipes which surround the converter and ensure that it sits tightly in place. If your converter comes with these then you will need to install them before you put in the converter itself.


There should be an arrow on your new catalytic converter to show you which way round it should be installed. You will also need to make sure that the right side is facing down when you put it in place. Exhaust Repairs


The next step is much easier if you borrow an extra pair of hands to help you. Holding the converter and working on it at the same time is no easy matter, so getting someone to hold it in place whilst you work on the bolts would be the best way of going about it.


Tighten the nuts as much as you can using just your fingers to start with. It will be easier to align all of the bolts in all of the bolt holes if you do not tighten them completely until all 4 are in place.


Most leaks in exhausts are due to loose bolts, so make sure that you tighten the nuts as much as you can.


Reposition the oxygen sensors and secure them in place. Double check that the wiring is correct, otherwise you could trigger dashboard warnings.


Once everything is back in place, it is extremely important to get your exhaust checked. Your car will need to pass an emissions test to check that it is safe for use on the road. The catalytic converter is an essential part of your car, and getting its installation wrong could have serious repercussions on your vehicle and the environment. If at any point during the installation you have any doubts or questions then you should take your car straight to a garage to have it looked at by a professional – this really is imperative!
Get up to 3 quotes for an exhaust repair job now

All about Exhaust

Get 3 free no obligation quotes now Safety and convenience at Autobutler

Get 3 quotes and compare quotes on exhaust

Quick and easy
Let us do the leg work. We will get 3 quotes from quality garages near you within 48 hours. And if it's urgent we can help you even faster.
Only quality garages
All our garages strive to give you the most accurate quote for your repairs, so please be as detailed as possible.
Need help?
If you are finding anything confusing or would like to chat about your vehicle with our in house mechanics call us on 0800 048 8195.
Get full security
All our garages are peer reviewed by car owners like you

Need help with your car?

Autobutler connects approved garages and car owners together. Our garages are ready to help you today.

Get your quotes now