Is It Safe To Drive With a Bad Catalytic Converter

If you are experiencing a loss of power and you suspect that your catalytic converter is going bad, you may want to consider is it safe to drive with a bad catalytic converter.

Is It Safe To Drive With a Bad Catalytic Converter

Is It Safe To Drive With a Bad Catalytic Converter

Is it safe to drive with a bad catalytic converter? It is not safe to drive with a bad catalytic converter because it can make your engine overheat. When your engine is running, the temperature in the cylinder is roughly about 2,500 degrees Fahrenheit. When the exhaust valves open up, the exhaust goes down through the manifold and into the catalytic converter. If the catalytic converter ever becomes clogged for any reason, all that pressure buildup and heat from the combustion chamber will stay inside the engine and it will cause the engine to overheat.

The catalytic converter has a task to reduce the harmful exhaust gases that are created in the combustion chamber before releasing them into the atmosphere. This task is very important. Because of the circumstances under which the catalytic converterOpens in a new tab.

Simply put, it is not safe to drive with a badOpens in a new tab.

If the catalytic converter is clogged, that pressure buildup and heat will just go back into the engine. Meaning, the heat and the gases will stay in the engine. Because of the excess heat, the engine can easily overheat.

What Are The Most Common Signs Of a Bad Catalytic Converter

At some point, your catalytic converter will get clogged and go bad. It is inevitable. The trick is to know when it will go bad and to catch the early signs before it does damage to the engine. Here are the 4 most common signs of a badOpens in a new tab.

1. No Oxygen Sensor Codes

If you are running a diagnostic on your vehicle and you get a P0420 to P0439 error codeOpens in a new tab.

First, use a scan tool with a live data feature (check prices on amazon.com) and check for the P0420-P04399 catalytic code. Then, check for oxygen sensor codes. If there are no oxygen sensor codes, that means the catalytic converter is most likely bad.

Use a scan tool with a live data feature to check the downstream oxygen sensor as well. With the live data number, the downstream oxygen sensor reading should be steady and should fluctuate less which should indicate less activity. This means that the catalytic converter is working efficiently. If the number fluctuates rapidly, then that means the catalytic converter is no longer working efficiently and the catalytic converter must be replaced.

2. Performance Issue and Rotten Egg Smell

Usually when the catalytic converter is failingOpens in a new tab.

All of these symptoms are an indication of a blockage in the exhaust. Make sure the engine is not misfiring. A misfire can quickly destroy the catalytic converter due to unburned gasoline coming out of the combustion chamber and is dumped into the exhaust system.

3. Overheating and Hard Start

When the catalytic converter is completely clogged, this will prevent the engine from exhaling. The exhaust fumes have nowhere to go and the exhaust fumes will back up into the engine which will cause the engine to overheat.

Check the catalytic converter with an infrared temperature gauge. Start the engine and measure the front and back of the catalytic converter temperature. The backside of the catalytic converterOpens in a new tab.

If the exhaust is completely clogged it can prevent the engine from starting. At this point. you should check the back pressure on the exhaust system with a backpressure gauge.

4. Perform a Visual Inspection

First, visually inspect the catalytic converter or exhaust manifold for cracks. Next, with the engine off and cooled use a rubber mallet and tap on the catalytic converter. If it sounds like marbles bouncing around, that means the catalytic converter is already bad.

How To Clean The Catalytic Converter Without Removing It

PENTAX Image

Replacing a clogged catalytic converter can cost up to $1000. A check engine light might come upOpens in a new tab.

1. Run a diagnostic check

To make sure that your catalytic converter is bad, you will have to run a diagnostic with a diagnostic tool (check prices on amazon.com). If you are getting error codes P0420 to P0439 or oxygen sensor codes, then your catalytic converter is clogged.

2. Make sure that your fuel tank is half full

Before you start, you need to make sure that your fuel tankOpens in a new tab.

3. Add the catalytic converter cleaner

There are a lot of catalytic converter cleaning products available. I usually use the Cataclean (check price on amazon.com). It is working just fine. If you have another cleaning product, go ahead and pour that one in the gas tank.

4. Run your vehicle for 30 minutes

Once you pour the catalytic converterOpens in a new tab.

5. Run diagnostics again

If your catalytic converter was just clogged and not cracked or broken, you should no longer receive error codes and the check engine light on your dashboard should turn off itself.

Vide Polowenski

General Mechanic with over 20 years of experience specializing in General mechanics, exhaust systems, fuel systems, and fuse-related problems.

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