Bad Throttle Body Position Sensor Symptoms – Which Are The Symptoms?

So, are you experiencing some lack of power in your car and the engine just doesn’t feel right although everything is in perfect working order? You probably experience bad throttle body position sensor symptoms. The throttle body position sensor or TPS is essential in power delivery and if it’s not working properly your car would not accelerate. And we are going to answer all the questions about this sensor.

• What Is A Throttle Position Sensor?
• Bad TPS Sensor Symptoms
• How To Diagnose A Bad TPS?
• How To Replace TPS Sensor?
• Cost To Replace
• Conclusion

It is a good thing that you started to look online for help and that you trying to learn more about the problem with the car not accelerating. Cause we are going to teach you how to troubleshoot. Troubleshooting is mastery by itself and will be a great aid to you in order to discover problems such as this one.

That’s why we are here to help you out and guide you through the whole process of diagnosing a bad throttle positioning sensor. This sensor is essential in order for your car to be properly working and deliver a good performance. Without this sensor, you will experience poor work from the engine and extremely bad fuel economy. But how can I learn to troubleshoot my sensor?

Don’t worry, in this article, we are going to teach you everything you need to know in order to recognize a bad or failing throttle body positioning sensor. We will start from the basics and learn what this sensor is all about then we are going to cover the bad throttle body position sensor symptoms. Then we are going to cover how you can fix this problem DIY and also how much this sensor is going to cost you. So, let’s dive into the article.

What Is A Throttle Position Sensor?

The throttle body position sensor is a component that is mounted on the throttle body. This component basically sends information to the PCM about the throttle body flap location.

Based on how much the flap is opened the PCM receives the data and then the PCM decides how much fuel to dump into the cylinders.

How this sensor works is pretty simple. Inside the sensor, there is a potentiometer. When current is passed through the wire the potentiometer needle moves and based on that input sends the right information to the PCM. If the input is wrong and the sensor does not work properly you will get a P0122 code.

This input then is used by a few components inside of your engine and that are the traction control, ABS system, fuel injectors, and cruise control. So, considering that even the safety systems depend on this data, then you can imagine how they would work without a proper working throttle body position sensor.

That’s why you have to learn the bad throttle body position sensor symptoms and we are going to cover them in the next chapter in great detail.

Bad Throttle Body Position Sensor Symptoms

Like with every other component on our cars similarly with the throttle body positioning sensor. When this sensor gives up it throws a check engine light on the dash and also develops some bad throttle body position sensor symptoms. But which are these symptoms of a bad throttle body? Let’s find out.

1. Check Engine Light Code P0122

As we mentioned. When the throttle body position sensor is failing it develops symptoms and first in the line of symptoms that this problem creates is the check engine light.

This is because the throttle body position sensor is connected with the PCM. Since the PCM records and evaluates every bit of data that it receives. When it receives too many errors from the throttle body position sensor it starts to react and will try to alert you.

And which is the way that it tries to alert you? By throwing a check engine light on the dash. This check engine light you will probably not know why does it show up in the first place. That’s why you need to start troubleshooting as we mentioned in the introduction.

Knowing to troubleshoot is going to tell you a lot about your vehicle. And for this job, you will need an OBD2 scanner tool. This tool is essential when you want to diagnose an issue. Luckily these OBD2 scanners can be found at your local parts stores or online on stores like Amazon or Ebay. And they are pretty affordable to get.

You need to plug the scanner into your OBD2 port and scan the car for problems. Then you have to look for these errors online and learn more about them. Some more advanced scanners will even show you the problem immediately. But these cost a lot more to get.

Nevertheless, after scanning the car for codes now it’s time to see what these codes mean, and then you can find a way how to fix the problem. If the code is P0122 then you know that you are dealing with bad throttle body position sensor symptoms and you need to fix this problem. But how? We will learn that at the end of the article.

2. Engine Does Not Run At The Right Idle RPM

If the throttle positioning sensor is bad the butterfly flap would not work properly. This will result in the flap either being too wide open at idle or too closed. This can be a frustrating thing because if the flap is open too much then the RPM will jump to 1,000+ which is too much considering that the average idle RPM should be 800 on most cars.

This increase in RPM will also be accompanied by a growling sound of the engine and you will have the impression that someone else is pressing the gas pedal which in reality is not the case.

Or if the flap is too closed then you can expect that the engine RPM will drop significantly and you will have the notion that your engine is dying. In this case, the engine will work with below 800 RPM. And if the RPM drop significantly that means that the injectors will be injecting less and less fuel into the system. Resulting in engine shutdown since the engine would not have the right amount of fuel to continue the combustion process.

This symptom along with the check engine light and the code P0122 are some of the most common bad throttle body position sensor symptoms that appear and trouble many car owners and can ruin your day.

3. Poor Engine Work Because Of Lean Air To Fuel Mixture

If the sensor is bad and doesn’t react to your throttle input then you may also suffer some poor engine work.

This poor engine work is because the engine receives a lot of air but the computer doesn’t record this input from the gas pedal. This means that there will be too much air and too little fuel dumped from the injectors.

This will result in lean air-to-fuel mixture. The average air to fuel mixture is 1.47 to 1. This means 1.47 of air and 1 fuel. If the air density is above 1.47 you are going to get lean air to fuel mixture issue and big power loss.

This problem with the lean mixture will also be damaging for the spark plugs, O2 sensor and you will have many more issues that we are going to cover next because they deserve their own chapter as one of the bad throttle body position sensor symptoms.

4. Engine Tries To Stall

Another symptom of a lean air to fuel mixture caused by a bad throttle body position sensor is the problem with the stalling of the engine.

If the mixture is too lean the engine will try to stall all the time. It will not be able to hold the RPM and the RPM will start to drop continuously and the engine will not run right anymore.

If the engine tries to stall on you, then this is one of the possibilities that the sensor of the throttle body is bad and has to be replaced.

If you get a check engine light and you also get the code P0122, then you can bet that this sensor is bad and your engine is continuously trying to stall on you.

The best thing in this situation is to get a new sensor from your local parts store and replace the old one. How you can do that we are going to discuss later in this article but first let’s finish the bad throttle body position sensor symptoms because everyone should know the symptoms in order to diagnose this issue.

5. Engine Is Misfiring

Another symptom that is attributed to the lean air to fuel mixture are engine misfires. This symptom is hard to diagnose and you need to have a good ear in order to notice if the engine is misfiring.

Usually, when the engine is misfiring you will notice uneven work from the engine and from the exhaust as well. If you put your hand on the exhaust you will notice how there is a low amount of gas flow and suddenly a pop is heard in the engine and the gas flow is increased and then returns to normal. This is a clear sign that the engine is misfiring and all this is attributed to a bad throttle body positioning sensor.

If this is the case, the best thing is to diagnose the problem by connecting an OBD2 scanner to the computer and see what types of errors the computer makes. If there is an error P0122 code then you know that the throttle positioning sensor could be one of the culprits for this issue and you need to solve this problem ASAP.

6. Bad Spark Plugs – Bad Throttle Body Position Sensor Symptoms

If you run your car on a lean air to fuel mixture that is attributed to a bad throttle body positioning sensor and you experience bad throttle body position sensor symptoms one of them would be as well the spark plugs.

You can check the spark plugs pretty easily. You just need to remove the coil pack and then unbolt the spark plug. If the spark plug has an orange color and is blistered this means that the spark plug is fouled and has to be replaced. You can replace the spark plug but the problem will stay.

That’s why you need to investigate this problem deeper and see what is the real cause. Scan the car for codes and if you get the code P0122 it means that your throttle body position sensor is bad. Replacing the sensor is probably going to help you out resolving this issue and how you can do this work we are going to discuss in one of the next chapters.

How To Diagnose A Bad Throttle Body Position Sensor?

The easiest way how you can diagnose a bad throttle body position sensor is to scan the car with an OBD2 scanner. A quick scan is going to tell you a lot when it comes to the overall health of your car and will help you troubleshoot components that are possibly faulty. Since you will get a ton of error codes if there is a problem with your car.

You can get these scanners cheaply online. But in order to get a good one that will tell you a lot. Make sure that you get one that you can connect to a phone via Bluetooth. These scanners tell a lot more than the regular ones that have pixelated screens and will only tell you the error code and nothing else.

Specifically for this problem, you should get the error P0122. This error means that there is something wrong with your throttle body sensor and the problem needs to be further investigated. And how you can diagnose a bad throttle position sensor? And that is by using a multimeter.

Get a multimeter from your local parts a cheap one will do the job well. Here is a video of how you can test the throttle body position sensor with a multimeter at your house DIY.

How To Replace A Throttle Body Position Sensor?

Replacing a throttle position sensor is a fairly simple task extremely DIY-friendly work. The first thing you need to do is to get a new sensor.

The second step will be unplugging the positive cable from the battery. This will guarantee you that no problems appear during the installation process.

After this, you need to unplug the connector that is connected to the throttle position sensor. After this work, you can unplug the clips that are holding the sensor and remove the old sensor from the housing.

Then you can plug the new sensor in the throttle body housing and also connect the connector with the sensor. And lastly, you can connect the positive terminal to the battery. We are also going to attach a video for you to visualize how this work is done.

And since you are already there and you opened the throttle body housing it is also useful to give it a good cleaning in order to remove the dirt from the flap. This flap also knows to get clogged after many miles of driving.

Cost To Replace Throttle Body Position Sensor

The cost to replace a throttle body position sensor is between $20 and $50. Throttle body position sensors are fairly cheap and they are not that hard to find. You can find them basically in almost every parts store around the country.

This is the case because they tend to fail pretty often and during the ownership of your car, you are going to replace them once or twice for sure.

Also, try to get an OEM replacement part. The OEM parts are much better than cheap knock-offs that are everywhere. Sometimes is better to pay more than pay twice later. And don’t forget all the trouble with diagnosing the problem and learning all the throttle body position sensor symptoms. It can be a pain. That’s why to choose quality over the cheap price.

Can I Drive With A Bad TPS Sensor?

You can drive with a bad TPS or throttle positioning sensor but the performance of the vehicle will be extremely poor. The car will barely move and you will find it difficult to keep the car at a higher speed since there will be lean air to fuel mixture inside of the combustion process.

This in other words translates to low power and low ability of the vehicle to deliver torque at the wheels. You can also damage tour spark plugs as well as the O2 sensor if you run your car like this for a long time.

Conclusion – Bad Throttle Body Position Sensor Symptoms

In this article, we covered a lot. We learned what a TPS sensor is and how you can read the bad throttle position sensor symptoms. You need to learn these symptoms in order to diagnose this problem correctly.

We also learned how to diagnose a bad throttle position sensor using a multimeter and then we learned how you can replace this sensor at home using the DIY method. And finally, we covered the cost that is involved in replacing this sensor. The price is fairly affordable and you can find these sensors almost anywhere.

If you want to read more on sensor related problems you might like to check out our article on bad purge valve solenoid, or if you want to learn more about maintenance you can check out our article on tune up cost.  Also if you want to read more on engine related problems you might like to read our articles on white sludge on oil cap and engine rebuild costs.