Can a Clogged Catalytic Converter Cause a Misfire?

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Apparently, a faulty, bad, broken, or clogged component would definitely cause different unusual signs, but can a clogged catalytic converter cause a misfire?

Yes, a clogged can catalytic converter can cause a misfire. It can also cause roughly idling, and generally affect your engine performance.

But then, a clogged cat converter doesn’t instantly start affecting your engine. It starts with showing you different “minor” signs before the engine starts getting affected. Hence, it is important that you know the signs a clogged or failing “Cat” would trigger.

When you’re aware of these signs, if they start showing up when you drive, you’d know it is time to check on your cat converter. However, before we delve fully into the article, let’s highlight the things that clog up a catalytic converter.

Why Did My Catalytic Converter Got Clogged?

The common “culprit” is leaky hoses and channels. Yes, if oil or antifreeze liquid leaks into the combustion chambers, it can cause the cat converter to clog up, and here’s the explanation of how it happens.

As oil or antifreeze leaks into the exhaust chambers, it makes the carbon deposits and emissions from the engine thicker; thus, the carbon and soot keep coating the converter’s inner channels until it finally blocks it.

Oil is quite thick, we all know that, and when mixed with soot, it gets thicker – capable of clogging smaller pores and air passages. This will, of course, affect how the converter performs its functions, which leads to the unusual signs exhibited by a clogged converter.

Well, not only oil and antifreeze can clog cat converters, or cause them to fail. If another crucial component connected to your engine is faulty, it can indirectly affect the performance of the catalytic converter.

For example, a bad oxygen sensor or faulty spark plugs can force unburned fuel into the exhaust system, and that can clog the converter’s honeycomb air passages.

Now, with this explanation, let’s talk about how a clogged converter can cause engine misfire and rough idling.

Can a Clogged Catalytic Converter Cause a Misfire?

The simple answer is YES, a clogged converter can cause engine misfires. If you’re inquisitive about how that could happen, here’s the explanation.

Catalytic converters are connected directly to the engine cylinders; thus, they are considered as one of the crucial components of an engine. As you may guess, if anything connected to an engine fails, it’d definitely affect the engine.

That said, here’s what a clogged converter does; mainly, what gets clogged is the honeycomb catalyst chamber where the exhaust fumes and carbon emissions are removed from. With this chamber being blocked, exhaust fumes flow is restricted, and that can increase “back pressure.”

With the increase in backpressure, more heat and “harmful” carbon emissions are sent back into the engine. This causes the engine to do more work in an unfavorable environment, which is what could trigger misfiring.

Actually, if more heat and harmful exhaust fumes keep going back into the engine, that could cause rough idling, and in worse cases, fatal internal engine damage.

Since the emissions from the combustion chamber won’t be removed with the cat converter passageway is blocked, a clogged converter threatens serious engine damage.

Related Post: Torque Converter Failure Symptoms

What Else Can a Clogged “Cat” Converter Cause?

When your car’s catalytic converter is clogged, you’d most likely experience these symptoms:

Constant engine overheating
Rough idling
Unusual loud noise coming from the exhaust
Check engine light is on
Car refuses to start up
Increase in fuel usage, but decrease in engine performance
The P0300 random misfire code shows in your handheld troubleshooting device
Engine misfiring

What More?

So, can a clogged catalytic converter cause a misfire? Yes, it would, and not just that, it can cause serious internal engine damage. It is advisable that you quickly unclog your cat converter to avoid your engine being bombarded with loads of harmful fumes and sediments.

It is cheaper to get a new cat converter, than getting a whole new engine (when the old one gets wrecked due to the harmful emissions it receives from the faulty catalytic converter). Hopefully, this article has clearly explained your question, do have a great day ahead.