Security Shields for Catalytic Converters: Cat Security vs Miller

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.

 

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.

 

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

 

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

 

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

 

Has anyone tried the Millercat Deadbolt? Stainless Steel MILLERCAT Deadbolt for 2001-2009 Toyota Prius– MillerCAT Corp

 

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.

 

Catalytic Converters run at temperatures of 400 (F) - 1000 (F) so even if you live somewhere where it is in the triple digits like me, overheating is not something to worry about.

 

There's some cat shield designs that will run too hot... We've yet to compare temps on cat protection devices, but first we need to know exact temp that a cat runs best at. That's a measurement of not just external but also internal temp combined. We need charts and graphs to better understand optimal temps. Also possibly an option on vents while driving in hot weather if that's beneficial.

 

This video of Motorhead Garage will likely persuade you that the Millercat is the one that you should choose for your Gen 2 Prius.

You might also want to add my Cheap catalytic converter security bolt head blockers.

Really cheap catalytic converter security... | PriusChat

 

I’m reading through these posts. I found out about Cat Security shield by reading this article.

Toyota Prius Repair Shop Learns Why Cat Security Shield Is The Best Solution For Theft Prevention | Torque News

What are your thoughts on this? I was planning to have Toyota put the steel Miller cat shield on my soon to arrive Prius. After reading this I don’t know what to do. I guess the deciding factor is that the Miller cat shield doesn’t interfere with Toyota warranty.

 

i don't know what Luscious original design was but Miller and Cat are very similar, a thief probably does not care. they see a plate and they are like , calculating in their midn whether they have the time and tool to cut the plate off or not.

 

Meanwhile anyone that has the ability to cut sheet metal started selling cat shields and what once was a $400 part when first introduced are now selling for less than $40: https://www.ebay.com/itm/295459494707

 

It's the result of CNC laser. water jet and plasma cutters. In the old days, it was tedious hand drawings, layout and hand cutting or very expensive large "cookie cutter" like dies.

 

Yeah, laser cutters, hydro jets, plasma cutters... Pretty much anyone with modern equipment for cutting metal can make tons of these in a very short period of time.