Installed Cat Protector today

Simply done: A slight up and down bend over a 2x4 on each side.

 

No rattles with my Cat Security install (paid a shop $150 to do it; that's a reasonable price for Seattle.) I shudder to to think how long I would need to wait for a replacement if mine got stolen... we're not as bad as CA, but pretty damn bad.

 

Smart move. Avoiding the hassle and inconvenience factor is definitely worth the cost.

There is no issues with rattling on the Gen 4 shields. The issue occurs with those installed on the Gen 2 and Gen 3 Prius models.

 

I suppose I should let the shop know the potential for rattles, so they can check for that when they install the shield.

Florida and Washington State have cheaper labor than California, but I'm hoping to pay no more than $150 to have it installed.

 

On mine, I made two creases over a 2x4. If you look at the end from the back, the edge forms an upside down trapezoid with about a half inch down under the cat at the back edge. The front with the four holes that fastened to the mounts for the original heat shield remained totally flat.

The two outer wings were ben down and the inner parts are bent up. Now, I have perfect clearance.

 

I also installed the same one the OP did, using a mix of rivets and rivnuts. I added foam strips like Miller Cat includes but sadly mine still developed a rattle. It's not consistent so I've wondered if maybe it's not from the catalytic converter, especially since I also gave the shield a bend for extra clearance, perhaps not enough. Will have to pull it at some point and try again. The rattle is rather annoying.

 

The issue is not the front of the shield, and there is no need for the foam strips. Get under the car and hit the shield with your fist on the pinky end. If there is a rattle, you will find it.

No, I did not use the supplied rivets. I used the Miller Cat method with the rivet nuts. I had to drill only two holes for the rear rivet nuts. The extra rivets are dummies with the heads cut off and epoxied onto the shield.



When I first installed mine a year in June 2020, I hit it with my fist right at the furthest back place where it contacts with the catalytic converter and got the sound of contact. By pulling down the end I got, I got it to bend down enough clearance and never got a rattle while driving the car.

In May of this year, I took the shield down and found that there was a rub between the cat and the rear of the shield. While this would have been fine probably for the rest of the life of the car, I decided to eliminate the contact, So, I reinstalled it and pulled down the end again. Doing this, I noticed the natural stress bend lines and marked them with a Sharpie.

Then I took the shield down and made bends over the edge of a 2x4 along these lines to increase the angle of the natural stress bends. It didn't take much of an angle.

After remounting, I got at least a 5/8-3/4 inch clearance under the rubbed area. Now, the clearance is perfect.

This sounds complicated, but it took no more than 20 minutes.

 

If the shield is installed with rivets, any rattle can be remedied by driving a flat wooden wedge cut from a 2x4 until a 1/2 inch clearance can be had under the rear of the shield and the catalytic converter. The shield will "spring" back with each application of the wedge, but will eventually "set" the shield with at least a half inch of clearance. Getting at least a half inch of clearance means that you're done.

This would eliminate the need to remove the shield and making the bends.