FAQs— Subaru Catalytic Converter
You can do that by wearing a heavy-duty mechanic’s gloves and, with the back of your hands, gently brushing the exhaust tube. If you can no longer feel any heat, try to repeat the test without the glove. Just be careful to avoid getting burnt. If it is still hot, let it cool down for a few more minutes before trying to test it again.
You can still do the repair by yourself even if the cat con is welded to the exhaust system at its connection points. However, you should make sure that you have access to a sawzall as well as a welding machine and you know how to use such equipment safely. Remember that these are advanced tools and may be beyond your mastery.
Partially corroded and rusted bolts or those that have jammed into the nuts can really be kind of difficult to remove. It helps if you loosen up the said bolts by putting on penetrating oil and allowing the oil to seep into the bolts so that it can lubricate them for a few minutes before you remove them using an appropriately sized wrench.
If you want to check for exhaust leak without physically getting under the vehicle and checking the pipe, you can drive test your ride and observe the exhaust behavior while you drive. If you notice that the car growls louder than usual or when it rumbles more than normal, there may be a leak in the system. Alternatively, you can jack up your ride, start it in park, and slowly move a lit candle along the length of the exhaust tubing. The flame will wave or blow out when it gets in front of the leak.
This can affect the engine's capacity to rid itself of exhaust, therefore causing a big drop in your vehicle's fuel efficiency. Worse, the soot and debris can make the engine stall. When this happens, perform a backpressure test. Such test can be done by screwing a pressure gauge into the oxygen sensor's slot on the converter. When the engine is operating at 2,000 RPMs, the pressure reading should be less than 1.25 psi. If there’s congestion, you’ll get a higher reading.
Yes, a rubber mallet can tell you if it’s already time to replace your old converter. With the rubber mallet, give your catalytic converter a firm hit. If there’s rattling from the inside, that means the converter now needs replacement as its metallic catalyst has begun to crumble and corrode.
Yes, you can take the catalytic converter off your Subaru and try to clean it to eliminate the soot and debris that are causing the catcon to malfunction. You can clean it using compressed air or a catalytic converter cleaner. When using the former, you have to remove the core and use 90 psi maximum compressed air. This is enough to blow away ash, dust, and light accumulations. When using a catalytic converter cleaner, on the other hand, make sure to strictly follow the instructions that come with the cleaner for best results.
- I know that I can’t work on my catalytic converter while the exhaust system is still hot. How can I properly test the temperature of the system for me to know when to start with my cat con replacement?
- I was doing a DIY fix on my Subaru catalytic converter but I recalled that during the last time I had it replaced by a mechanic, it was welded in place. Is the job feasible for an amateur DIYer like me?
- During troubleshooting, I noticed that my Subaru catalytic converter is bolted in place. However, the bolts have already rusted. Any tips on how to properly remove such bolts?
- After installing my new Subaru catalytic converter, what are the easiest ways to check if my DIY task has caused exhaust leaks?
- What can possibly happen if my Subaru catalytic converter gets backed up with debris, soot, and other byproducts of exhaust?
- A friend told me that I can use a mallet to test my old converter. Is that true? If yes, how can I perform the test properly?
- Instead of replacing my dirty Subaru catalytic converter, can I clean it first? Is it worth a shot?
Subaru Catalytic Converter Buyer's Guide
- A catalytic converter, or a cat con, reduces air pollutants and toxic gases in the exhaust gas and breaks them down into less toxic compounds by using catalysts in the form of platinum or palladium.
- If you have a bad cat con, you’ll notice that your engine is performing poorly and doesn’t accelerate well. You’ll also notice that your vehicle will emit a dark exhaust smoke and a rotten egg smell. The underside of the car may also heat up.
- Consider the type and fit of the replacement cat con you’re going to buy. Also, make sure that it is compliant with the legislation in your state.
- The price of an OE replacement Subaru catalytic converter ranges from $40 to $1200.
Subaru as a company is driven by its principles of equity, diversity, and inclusion and wholly devotes its energy into making vehicles that last a lifetime. If your Subaru catalytic converter shows signs of breaking down, you’ll want a high-quality replacement part. This short guide will help you see the symptoms of a failing Subaru catalytic converter and give you some tips before buying a replacement part.
What is a catalytic converter and how does it work?
A catalytic converter, or a cat con, reduces air pollutants and toxic gases in the exhaust gas and breaks them down into less toxic compounds. The catalytic converter uses a catalyst in the form of platinum or palladium to coat the insides of a ceramic honeycomb structure. The ceramic structure is housed inside a muffler-like casing and is attached to the exhaust pipe of the vehicle.
There are two types of cat cons: two-way and three-way. Two-way cat cons are used in diesel-powered engines while three-way cat cons are more common and are used in gas-powered engines. In two-way cat cons, the catalyst converts carbon monoxide into carbon dioxide and breaks down hydrocarbons into carbon dioxide, and water. A three-way cat con does the same thing but it can break down nitrogen oxides back into nitrogen and oxygen as well.
Bad catalytic converter symptoms and their causes
Subarus usually have multiple cat cons that come in Y-pipe assemblies and are bolted onto both sides of the engine. Some newer models might even have a third or fourth cat con installed. Cat cons are susceptible to damage because of their location, structure, and types of substances that pass through them.
You’ll know that you’ll need a catalytic converter replacement if you notice more than one of the following symptoms:
- Reduced engine performance and acceleration
- Dark exhaust smoke
- Excessive heat under the vehicle
- The smell of sulfur/rotten eggs coming from the exhaust.
How to buy a Subaru catalytic converter
Before buying a catalytic converter for your Subaru, you’ll need to consider a few things first. Below are some things you have to keep in mind as you’re buying a replacement Subaru catalytic converter:
Two-way cat cons are usually used in diesel engines while three-way cat cons are used in gas-powered engines. Make sure you’re getting the right cat con type for your Subaru before buying a replacement part.
Replacement cat cons come in universal and direct fit. With direct-fitting catalytic converters, you won’t have to make alterations as they’re usually bolt-on parts. On the other hand, universal cat cons may need modifications and welding which might take up more time to install.
In January of 2009, the California Air Resources Board (CARB) passed a stricter regulation on the sale of aftermarket cat cons in California. In 2014, New York followed suit. If you’re from these two states, you’ll need to purchase a California emissions catalytic converter. Otherwise, you’re eligible to buy a federal emissions cat con.
How much is an OE replacement Subaru catalytic converter?
The price of an OE replacement Subaru catalytic converter ranges from $40 to $1200 and depends on several factors including the year and model of your Subaru.
You can browse for OE replacement Subaru cat cons at CarParts.com. Using the vehicle selector tool on the website, you can narrow down your choices to your Subaru’s specific year and model. You can also use the advanced search filter tool to indicate your preferences on brand, fit, location, and emissions regulation type. A Subaru catalytic converter replacement is typically sold individually, in sets of 2, or as an assembly.
How to Install a Subaru Catalytic Converter
Toxic emissions, low fuel economy, poor engine performance, and bad exhaust-this is what a faulty catalytic converter can do. If the device can't effectively transform toxic compounds such as hydrocarbon, carbon monoxide, and nitrogen oxide into less harmful substances, the bad catalytic converter can ruin your driving experience and the vehicle can fail the emissions test. Install a new Subaru catalytic converter. Here's how:
Required skill level: Intermediate to Expert
Needed tools and materials
- New catalytic converter
- Jack and jack stands/Hydraulic lift
- Penetrating oil
- Sawzall (for a welded-in catalytic converter)
- Welding machine (for a welded-in catalytic converter)
Preparing for the job
Lift the vehicle off the ground, not just one corner. Raise it with a jack and support it with stands or use a hydraulic lift. The vehicle has to be parked on a level surface. Don't start any work on the catalytic converter until you're sure that the vehicle's exhaust has cooled down. You have to slide underneath the vehicle to trace the lines of the exhaust and locate the catalytic converter (use the vehicle manual as a guide if you have to). See if the device is bolted or welded to the rest of the exhaust system. If it's welded, you need a sawzall or a similar tool and a welding machine in order to replace it. If you don't have access to these tools and don't have the advanced skills to handle these, it would be best to leave the job to a certified mechanic.
Removing the old catalytic converter
Pull out the oxygen sensor from the catalytic converter. Some catalytic converters are even equipped with more than one oxygen sensor. Use an oxygen sensor socket and ratchet wrench to remove it.
For the bolt-in catalytic converter
Apply some penetrating oil to the bolts to make it easier to undo them. Leave this on for several minutes before you loosen the bolts using a right-sized wrench. Start at the back end first and then at the front. Remove the rear bolts first before those on the front. Once all the bolts are removed, you can now detach the converter. Support the exhaust once the converter has been pulled out.
For the welded-in catalytic converter
Cut the converter out of the pipes where it's connected with a sawzall or a similar tool. The cut should be along or near the weld lines. If the converter can't be moved easily, you'll need a little help with the hammer to take this out its place. However, be careful not ruin any part with just a gentle strike or blow.
Installing the new catalytic converter
Note: Check the installation instructions or guide on the new catalytic converter. Installation or the steps for replacement will vary depending on the catalytic converter.
For the bolt-in catalytic converter
Slide in the gaskets that come with the new converter. Bolt-in converters may come with gaskets that sit within the pipes that are connected to the converter. Install these gaskets according to manufacturer instructions.
Set the new converter in place. Line it up and hold it in proper position. Make sure that this is in the right direction and it's facing the right side. Once properly placed, tighten down the bolts with a right-sized wrench. Start at the front and then at the back.
For the welded-in catalytic converter
Weld the converter using a welding machine (MIG welder, e.g.). Welding should be done by a skilled or trained welder. As you weld the device, the converter must be connected to the exhaust system pipes at both ends. Each weld should create an air-tight seal. Let each weld to cool properly.
After installing the converter, you can re-attach the oxygen sensor. Screw it back into place. See to it that the wiring is well and intact.
Testing the newly installed catalytic converter
Double-check the attachment to ensure that it's properly installed and connected. The bolts should be tight and there should be no leaks from the exhaust. Test it out. See how the vehicle runs.