Why installing a catalytic converter anti-theft shield is worth it

Whatever makes the installer/owner feel better, I suppose. In reality, choice of fastener (stainless steel or not, rivets or rivnut inserts and bolts, Torx or Allen or hex heads, etc.) makes no difference to a thief: their tool of choice appears to be the Sawzall, and Sawzalls cut through 1/4" aluminum plate as well as any other material, given enough time. It's not like they're stopping to carefully unfasten everything, as we can see with how they treat O2 sensors and coolant lines.

IMO, the benefit of these plates is in their deterrence. Anything that makes a car a less attractive target by making it take longer to get to the cat will decrease the likelihood that a thief will go after the cat in question rather than move on to an easier target. Conversely, if a thief really wants the cat under a shield, he'll get it if he's willing to risk the time, no matter what fasteners you use--but we're betting on him not being willing to take that risk, which I also think is a good bet.

 

Police: Prius crushes man who was under it trying to steal catalytic converter | News | kctv5.com

 

Miller now offers optional security bolts of their own design as an extra-cost option.

There are many different security-bolt head designs, but not of all them available (at least readily in the USA) on Metric bolts.

 

I'm planning a home-brew shield, and my thinking on the bolts is just to make it difficult for the thief. Not thinking it's possible to stop them, my aim is just to frustrate and slow them down, convincing them to move along to another victim or maybe even making an honest living.

So I'll use as many different fastener heads as I can - hex, Allen, Torx, Phillips, even slotted, and rivets, all of varying sizes, with some fake ones (not actually attaching anything) thrown in there for fun. All of them will be covered with epoxy to make it a little harder, and to be sure that they need to first do some work removing the epoxy before even figuring out what tool they need to go and get to finish the job ... on this bolt. Then the next one will be different. Mixing things up this way is really not much more difficult for me, but would comparatively add a lot for the thief to deal with.

An angle grinder would be able to make fairly quick work of all of them, and would not care about the epoxy or head variations, but if they have to resort to that, they'd be more likely to get burned by sparks, which I'd take as a partial victory.

In more general terms, I'm thinking that the more different tools you require them to have and use, the more of a deterrent it will be. I'm sure they'd most prefer to crawl under there with a sawzall and nothing else. A sawzall can cut a lot of things, but not really "all." It will do well on rigidly supported sheet. But not so well on flexible, compliant things like wire or expanded sheet steel. And not so well when there is something behind it that interferes with the sawzall's 1" motion. Painting the cat and the shield should be an easy thing to provide a deterrence.

I expect they will be more deterred by a home-brewed solution vs. a production version - similarly due to the uncertainty of not knowing what will be required. At some point, any of the production versions will be known, with optimal defeat procedures figured out - it the same way that I'm sure it is already well known what methods and tools work best on various years.

 

Exactly my thought. The thief would want a quick 'jack, saw, and grab'. If they see any deterrent, regardless of how it is attached, I bet they leave it and move on.

Hmm..so these shields are aluminum?! That seems odd. I would have thought stainless steel or something like that.

And this gets me thinking...how about some sort of deterrent that spews colored powder, ink...or something like that? Not sure how it would work...but it sure would be a surprise for the thief!

 

all. Would any of you be able to link to your recommended catlock and/or give some pros and cons for the different ones? I don't necessarily need one that's easy to install since I'll take it in to a garage/service center to install.

 

I bought the Cat Shield

Cat Shield — MILLERCAT - CARB Converters

not directly from the manufacturer but from an eBay seller who included an el-cheapo substitute for a real rivnut/nutsert tool.

I see that one of the other manufacturers has an additional piece that attaches farther back.

 

Tilt sensor

 

For those who are interested...
New version made of stainless steel

 

Are G3 cats being stolen?

 

A lot here in Canada ...

 

I suspect either aluminum or steel have roughly equal deterrent value: prospective thief takes one look (at either), and moves on. If they were going to try, they’d drill out the pop-rivets, regardless of shield material?

 

I agree , deterrent aspect more than a really high anti-thieft protection , if they are too lazy to have a real life job , they surely don’t want to have to work harder to steal it , they will simply choose another one....more and more Prius in this part of the country...

 

Didn’t know about aluminum rivets; IIRC you mentioned sub’ing SS rivets when you did an install?

 

I like the idea of these shields.
Deterrents.
+1 for the sicker idea.
+1 for stainless over aluminum rivets.

The thief will have what tools?
Drill, Sawzall, maybe a small socket set?
Will they have a torch?

The shield would increase the time to drill rivets and/or Sawzall noise to remove.
The torch, could be quiet.

The shield manufacturors have place inspection holes for Smog Centers to verify the cat.

Local dealer is having a special...shield and install $450. (Calif labor rates LOL)

FWIW an air compressor rivet install tools is so much easier than a manual rivet tool.
Can be done on jack stands.
Watch for clearances and rattles from the shield, especially with a Prius v model.