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.

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.

Is It Safe To Drive With a Bad Catalytic Converter

Is It Safe To Drive With a Bad Catalytic Converter

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 converter works, it is inevitable that it will get clogged at some point.

So the question is: Is it safe to drive with a bad catalytic converter?

Simply put, it is not safe to drive with a bad catalytic converter. It is not safe for the environment as well as for the vehicle. When combustion occurs in the combustion chamber, the temperature reaches up to 2,500 degrees. The exhaust gases together with the heat are released into the manifold and then into the catalytic converter.

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 bad catalytic converter.

1. No Oxygen Sensor Codes

If you are running a diagnostic on your vehicle and you get a P0420 to P0439 error code, that is an indication that the catalytic converter is no longer working efficiently. When the catalytic converter reaches a certain inefficient level, the computer will trigger a code and turn on the check engine light.

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 failing it will emit a rotten egg smell followed by engine performance issues such as rough idle, lack of power, stalling, sluggish performance, black smoke coming out of the exhaust, and vehicle unable to go faster than 30 miles per hour.

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 converter temperature should not be lower than the front temperature. If it is, that means the catalytic converter is clogged.

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 up even if you only lose 5% efficiency of your catalytic converter. So, before you spend money on a new catalytic converter, why don’t you try and clean your catalytic converter without removing it.

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 tank is at least half full before you pour the catalytic cleaner solution. Your vehicle would need to run for at least 30 minutes and you will need fuel.

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 converter cleaner into the fuel tank, you can either rev your engine on 2500 RPMS for 30 minutes or you can drive in on the highway for over 150 miles at higher speeds. This will make sure that the cleaning solution from the fuel tank will pass through the catalytic converter and unclog it.

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.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Content