Top 5 Best Car Alarms for Catalytic Converter Theft (2024)

Last updated Feb 15, 2024

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Car owners, particularly Toyota Prius owners, are facing a new threat. In recent years, catalytic converter theft has taken the country by storm. Thieves are now collecting dough on the black market by selling stolen catalytic converters to scrapyards. Scrapyard owners then pass the converters along the chain to have the precious metals extracted. While a single theft won’t earn big bucks an established catalytic converter theft racket can and will. Certain car owners must now consider investing in the best car alarm for catalytic converter theft to protect their investments.

Keep in mind that an alarm is only part of an anti-theft system. Primarily, an alarm is a great deterrent since the high-dB alarm sound will tell thieves to scram. In this article, you’ll discover car alarm systems that work well to help you prevent catalytic converter theft. Also, you’ll pick up tips on how to prevent theft along with reviews of each alarm. By the time you leave here today, you’ll be well on your way to beefing up your car’s security.

Top 5 Car Alarms to Prevent Catalytic Converter Theft

Product Description
#1) Viper
Responder HD

  • Security: 2-Way, 6-Tone Siren
  • Range: 1 Mile
  • Sensor: Shock
  • Model: 5906V
  • Price: $$$$
#2) Compustar All-in-One 2-Way Remote Start + Alarm Bundle

  • Security: 2-Way, 105 dB+ Alarm Siren
  • Range: 3000 ft
  • Sensor: Shock
  • Model: CS7900-AS
  • Price: $$$
#3) Prestige Two-Way LCD Confirming Remote Start & Alarm

  • Security: 2-Way, Multi-Tone Mini Siren
  • Range: 1 Mile
  • Sensor: Shock w/ City Mode
  • Model: APS997Z
  • Price: $$
#4) Wsdcam Wireless Anti-Theft Bicycle Motorcycle Alarm

  • Security: 113 dB Alarm
  • Range: 7-Level Adjustable Sensitivity
  • Sensor: Motion, Vibration
  • Model: WSDUS0270
  • Price: $
#5) Directed Electronics Install Essentials Dual Zone Motion Sensor

  • Security: Dual-Zone
  • Range: Adjustable
  • Sensor: Motion
  • Model: 508D
  • Price: $

Best Alarms for Catalytic Converter Theft Reviewed

When choosing a car alarm to prevent catalytic converter theft, there are several routes to take. In most cases, a shock sensor is enough to get the job done. If you own a Prius or Honda Element, a thief will need to use a jack to access your exhaust. For this reason, a shock sensor will detect the jack and sound the alarm.

If you own a raised truck, then your best bet is to go with a shock sensor and a motion sensor. A motion sensor will catch thieves who don’t need to use a jack. Always keep in mind that any car alarm is a deterrent. The high-dB alarm sound will alert people nearby that your car has been compromised by an intruder.

However, that’s as far as an alarm will go. For complete catalytic converter theft prevention, it’s also advisable to invest in the best catalytic converter anti-theft device, such as a shield. By combining these two devices, you give yourself ultimate protection against theft.

So with that in mind, it’s time to take a closer look at each of the alarm systems in the reviews below.

#1) Viper 5906V Responder HD

Viper is one of the leaders in the car alarm space, and the Responder HD is one of Viper’s most advanced car alarm systems. With this unit, you have the flexibility to beef up your car security to the highest level while enjoying the perks of remote start and other options. Next, the 1-mile range is one of the longest you’ll find.

Once installed, you’ll receive alerts directly to the beautiful OLED display. In the case of catalytic converter theft, you’ll always know when someone tampers with your car. The base package includes Viper’s Stinger DoubleGuard Shock Sensor, which has the ability to detect both light and heavy impact. For Prius owners, this sensor will surely detect a jack.

Beyond those capabilities, there’s always the option to customize this system to your liking for added security. Lastly, Viper systems come backed by a limited lifetime warranty and a 60-day satisfaction guarantee. All in all, Viper is the first place to look if you want a reliable car alarm system with all of the bells & whistles.


  • Crystal-Clear OLED Display
  • Includes the Stinger DoubleGuard Shock Sensor
  • Fully customizable commands and alerts
  • Remote start system with interior vehicle temperature readings
  • The option to pair a 2nd vehicle
  • Long rechargeable battery life


  • Warranty service can be iffy
  • Professional installation required
  • Remotes may feel large to you

#2) Compustar CS7900-AS All-in-One 2-Way Remote Start + Alarm Bundle

If you’re not a fan of Viper alarm systems, then a worthy alternative is Compustar. With a 3000 ft range, you get over 1/2 mile of coverage, which is sufficient in most circumstances. Next, this complete kit delivers just about everything you could ask for from an alarm system. The user-friendly LCD remote allows you to easily set up your alerts and keep tabs on your vehicle at all times.

With the dual-stage shock & impact sensor, you’ll always be one step ahead of thieves. Then, there’s the 105 dB alarm that’s guaranteed to act as more than just a mild deterrent. With the 2-way remote, you’ll always receive timely confirmations and alerts. In the event that someone does trip the shock sensor, you’ll instantly receive an alert to the remote when you’re unable to hear the alarm.

Finally, this system also features remote start and keyless entry capabilities for added convenience. For added assurance, Compustar provides a 1-year warranty on its remote.


  • A good affordable alternative to the Responder HD
  • Interactive LCD remote with 2-way alerts
  • Dual-Stage Shock & Impact Sensor
  • Remote start and keyless entry capabilities
  • Silent arm/disarm
  • The range estimate delivers


  • Installation may require additional parts
  • Instructions may feel vague to DIYers
  • The screen may show scratches easily

#3) Prestige APS997Z Two-Way LCD Confirming Remote Start & Alarm

Landing at third on our list is another affordable car alarm for catalytic converter theft. At the time of this writing, the Prestige system is more affordable than our top two picks. Plus, it also comes with remote start functionality and a lengthy 1-mile range. The included remote features an LCD with clear updates and notifications.

One cool feature that smart device fans will enjoy is the ability to use app control via your smartphone. With this ability, you essentially have the option to turn your phone into the remote, eliminating the need to carry a separate remote at all times. Included in the package is a dual-stage shock sensor with a nifty City Mode for city dwellers who want to protect against catalytic converter theft.

Other highlights include the multi-tone alarm, automatic arming/locking, and remote panic in all modes. Lastly, this Prestige system does come backed by a limited lifetime warranty for added peace of mind.


  • Good bang for your buck
  • Lengthy 1-mile range
  • Optional smartphone control via app
  • Included shock sensor with City Mode
  • Remote panic in every mode
  • Limited lifetime warranty


  • Programming the remote requires a learning curve
  • The remote could be more durable
  • High replacement cost for broken remotes

#4) Wsdcam Wireless Anti-Theft Bicycle Motorcycle Alarm

Alright, now if you want to skip over installing a complete alarm system and take the cheap route, the Wsdcam is worth a look. While not specifically designed to prevent catalytic converter theft, it can work as a strong deterrent. The beauty of this product is the seriously loud 113 dB alarm. There’s no way that anyone in the vicinity wouldn’t hear this alarm once it’s been triggered.

Now, the key here is to temper your expectations because using one of these will require additional time. Since your exhaust system gets hot while driving, you’ll want to remove this little alarm while driving. Clearly, the need to remove and replace the alarm each time you park could become tedious depending on how often you park.

Regarding functionality, this handy alarm detects both motion and vibration. Consequently, you have the option to use it as a standalone alarm for cat converter theft or use it along with your existing car alarm for added security. The main thing is to consider how prevalent cat converter theft is in your area and whether you own a heavily targeted vehicle, such as an older Prius.


  • Much cheaper than purchasing a complete car alarm system
  • Adjustable motion and vibration sensor
  • Easy to place close to your catalytic converter
  • Includes a remote
  • IP55 waterproof rating for outdoor use
  • Ample volume at 113 dB


  • Recommended to remove it while driving
  • Nothing more than a deterrent
  • No notifications when the alarm sounds

#5) Directed Electronics 508D Install Essentials Dual Zone Motion Sensor

The final option is a universal motion sensor that can be added to a new or existing car alarm system. If you’re handy with alarm installation, chances are you’ll be able to install it yourself. For everyone else, stick with professional installation to ensure you get what you paid for. As for the “dual-zone” tag, this allows you to customize the sensor to create two zones around your vehicle.

If a person enters the first zone, the sensor will cause your alarm to make a chirping sound. Once the second zone is breached, the sensor will sound the car’s alarm. When installed together with a Viper system, you’ll also be able to receive alerts to your remote when the motion sensor detects motion. Since the catalytic converter is located beneath your car, the sensor can be programmed to sound the full alarm when someone is beneath your car.

For Prius owners, an additional motion sensor might be overkill. However, for owners of trucks and SUVs, the addition of a motion sensor is advisable to prevent catalytic converter theft.


  • An excellent upgrade to an existing car alarm system
  • Compatible with popular car alarm brands, including Viper
  • A good choice for raised truck and SUV owners
  • Dual-zone technology
  • Receive alerts to your alarm remote when someone approaches your vehicle
  • A warning chirp when the first zone is breached


  • Professional installation recommended
  • Sensitivity must be dialed in to prevent false alarms


Below, we answer common questions related to using a car alarm to prevent catalytic converter theft and other important topics.

Do I need an existing alarm system to protect my catalytic converter?

It depends on whether you want to invest in a complete car alarm system or simply use a motion-activated alarm such as the Wsdcam. A full alarm system gives you greater security, more convenient features, and the all-important alerts to know when someone is trying to infiltrate your exhaust system. Since most car alarms include shock sensors, these sensors will detect the use of a jack.

Is catalytic converter theft on the rise?

Sadly, the answer is yes. In recent years, thieves have begun targeting catalytic converters since they’re easy to steal. Plus, there are more Prius owners. Prius catalytic converters are worth more, hence the reason why thieves target Prius cars, particularly older models.

How does the catalytic converter alarm work?

Depending on which alarm you choose, the system utilizes sensors that catch thieves in the act. For instance, a car alarm with a motion sensor will detect when thieves are below your car. As a result, the sensor will sound the alarm.

Will a car alarm stop catalytic converter theft?

A car alarm does not have the ability to physically stop thieves from stealing your cat converter, however, it does act as a strong deterrent. With a high dB alarm and alerts, you give yourself a much greater chance of protecting your investment. Depending on your car, it’s best to opt for professional installation to ensure you install the proper sensors to keep thieves at bay.

Does insurance cover stolen catalytic converters?

As with all insurance policies, it’s important to read the fine print to identify what is and isn’t covered by your policy. For Prius owners and other heavily-targeted vehicle owners, always check to make sure that your insurance policy covers catalytic converter theft. Because no matter how many precautions you take, there’s always the chance of theft occurring.

Bottom Line

For high-risk vehicles such as the Prius and Element, a car alarm is a must-have car security feature. The high dB alarm acts as a powerful deterrent to keep thieves away from your exhaust system. With a properly installed car alarm, anyone close to your car will hear the triggered alarm system.

Additionally, a good system will include a 2-way remote that sends you direct alerts anytime someone approaches your vehicle. All in all, when shopping for the best car alarm for catalytic converter theft, stick with one of the systems mentioned in this article or with the manufacturers.

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