Security Shields for Catalytic Converters: Cat Security vs Miller

Discussion in 'Gen 2 Prius Main Forum' started by jensey, Jan 29, 2021.

  1. jensey

    jensey Junior Member

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    Grrr! Thieves got the catalytic converter on my 2006 (in Santa Monica, CA). The repair shop was lucky to find the OE replacement (required in CA) considering all the other victims out there (2 other Priuses in the shop for the same thing when I brought mine in). So I’m trying to decide which anti-theft shield to install. I’ve tried to read through all the previous threads but wanted to post my query as well.

    The Cat Security from Cap City Muffler seems to be the predominant product. A similar device is the Cat Shield from Miller Cat. Prices are about the same. Has anyone had any recent experience with either of these? (I’m not considering any of the cage-like devices.)

    Cat Security has many more Toyota dealerships and local repair shops (Los Angeles area) than Miller. Miller says they are a Toyota approved ‘associated products’ supplier despite their smaller market penetration.

    Here’s the main difference: Cat Security now sells an additional plate (Ultimate Protection Upgrade) which attaches vertically to the rear of the shield to block that access point. This seems to be a worthwhile expense. I spoke to Miller who says they’re in the process of testing what probably is a similar add-on, though they were hesitant to reveal exactly what it is. At this point, I plan to get the Cat Security over the Miller Cat because they offer the upgrade plate.

    Thanks.
     
  2. wasambi

    wasambi New Member

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    MillerCAT is the way to go. I did a lot of research after having to pay $2000+ on catalytic converter repairs for my Prius.

    Here's why I chose MillerCAT over Cat Security:

    1) Once you put on Cat Security, you can't add any new upgrades to boost your security because it's locked with a one way screw. If someone messes up your shield with a sawzall or whatnot, you'll have to rip off the whole shield and you got it, drill another one way screw in a another hole to hold it in place. How many holes are you gonna mess up before you run out..

    2) Galvanic corrosion. This is HUGE. I keep bringing this up in every post because it is a BIG DEAL that a lot of people don't realize. Cat Security uses one way screws that penetrate the frame of your Prius. Not only can you not take it out, but also, you're looking at permanently damaging the structure of your vehicle where the screws are installed. When dissimilar metals touch, you'll start to see galvanic corrosion. It's going to eat away at the metal frame over time. MillerCAT's Cat Shield on the other hand uses zinc coated rivet nuts to separate the two metals. Look it up on google, the damage it does is pretty bad.. especially if you're located in the east coast. I'd rather spend my money on a company product that has done thorough research and is an expert in the industry.

    BTW - There's a reason Toyota chose these guys over Cat Security and they're usually REALLY strict and picky on who they allow onto their Associated Parts catalog.

    I'd also call the Toyota Dealerships to see which cat shield they're using because I called a few and they only carry MillerCAT even though it's listed on the Cat Security website. Seems like they keep all the dealers and shops listed even though the dealerships don't use them. And spend a TON on advertising to seem like the predominant product.

    I hope this helps.
     
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  3. FLdreamin

    FLdreamin New Member

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    You must've been reading my mind. I recently bought an '08 and was considering the Ultimate Protection Upgrade as well but haven't pulled the trigger yet. Will be following this thread for more info. Sorry to hear about your stolen cat.
     
  4. PriusCamper

    PriusCamper Senior Member

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    Due to climate change the place you live is gonna get crazy hot in coming years so when it comes to protecting from theft, also consider protecting your cat from running too hot by maximizing ventilation.

    As in any added feature that covers even more and makes the cat run even hotter is not advised. Also keep in mind the purpose of the shield is to act as a visual deterrent, not to stop someone who's determined to steal your cat. Thieves can steal a Gen2 cat in less than 60 seconds, so anything that slows that time down will get them moving on to the next car...

    So I wouldn't be too worried about which one is better and instead go with which one is cheapest. This one is only $110: CDP Cat Shield 2004-2009 Prius Catalytic Converter Protection / Cat Shield | eBay
     
  5. SFO

    SFO Senior Member

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    Think it was a lady in the UK that mentioned a "shield" wasn't effective during the second theft, but common sense would also say that it should create a deterrent which may cause the thieves to go across the street or up the block to the neighbors easier option.

    Using an angle grinder, or a high speed cutting wheel, these security shields might increase the theft time from 1 minute to 2 minutes. Basically if they don't have the tool, or don't have an extra minute, you might be safe until the next thief comes along.

    If spending over 2k+ for a replacement (CA/NY/MA), then spending an extra 200 trying to protect it might be a worth while gamble. I've seen some shields sell online for around 100, and install shouldn't take but an hour of labor.

    Now that we have that out of the way, @Kaptainkid1 has been quite successful over the years (knock on wood) with a DIY shield that would cost the same or less. Read through this thread, paying attention to this post with the step by step, including materials : Preventing Catalytic Converter theft | Page 2 | PriusChat
     
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  6. EricTech

    EricTech New Member

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    I can install a shield on your Prius in the San Francisco area.
    I'm mobile to your home or work
    Eric 650-518-4965
     
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  7. Central Virginian

    Central Virginian Junior Member

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  8. PriusCamper

    PriusCamper Senior Member

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    First time I've seen this mentioned on here. I guess it could help a little, but it's hard to tell with the pics they provide. It seems to help protect from a sawblade, but not from using a ratchet to remove the bolts that connect cat to exhaust header, or alternatively stick a blade up in the slot and cut through the bolts.
     
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