I don’t really want my catalytic converters stolen. I can DIY a replacement setup with racing cats and exhaust tubing, but I’d rather not. Plus I recently had my truck prowled – they got about two dollars in quarters and some covid masks, and I’m still mad about it.
While researching cat shields for my 4×4 Tundra I found rave reviews for the Millercat cat shield. “Direct fit,” they claim. “Works with the TRD Pro skid plate,” they say. One video even included where to drill holes in the frame for rivnuts (rivet nuts/ threaded inserts) so we can use the rear shield extensions on our not-2018 to 2021 Tundras. “This is perfect!”, I thought.
I’ll start with the Pros: the company was very fast to respond to a silly question I had (which is answered on their site, but I’d simply missed it). I ordered the shield for my Tundra (plus rear shields) and for my partner’s 4Runner. The shields arrived quickly, both main shields are very sturdy aluminum and they’re cleverly flat packed; the security fasteners give it dimension. Additionally the fasteners are installed from the “up” side of the shield, so removing them from below should require drilling. Note these are not tamper resistant torx fasteners, they’re a five lobe design with a pin in the center. That’s great because they’re harder to find but it did mean I had some issues installing these “security torx” fasteners, as they’re referred to in several places, when my actual-factual security torx keys didn’t fit in a cramped space.
The Neutrals: the website “recommends” the AVK rivnut tool. For the 4×4 Tundra this is not really “optional”. I tried to raise the transmission and there is no way I’m getting my two-handled rivnut tool in that space. Save yourself the headache and spend the $20. The video that you’ll find on YouTube if you look for this topic is “easy mode”. The 4×2 Tundra without TRD Pro skid plate should genuinely be a 30 minute install.
The not-so-goods: The instructions indicate there should be a “R” and “L” on the side pieces to help with ensuring the correct side; I could not find any markings. The photos and sketches in the print instructions didn’t really help me understand the situation any better. The “easy mode” video referenced above was very helpful in this regard. Yes, this *does* work with the TRD Pro skid plate. But the instructions are silent about how to do that. I’ll add my experience below. The rear shields are disappointing. They are thinner than the main shields and they don’t extend as far back as I would expect. If they were any longer Millercat would have to include nuts with handles welded to them to reach the end of the bolts in the crossmember. I’ve seen that done for bolt-on rock sliders, and I imagine something similar could work here. I also think they may have shipped the wrong part for the passenger side; I cannot rotate, flip or turn it in any way to get the holes to line up. I hope customer service has a prompt response.
Overall I give this 3.5 stars. Harsh! I know. But the shield is $520, the rear extensions are $70 plus there’s shipping. The instructions are not easy to follow and they offer no guidance for installing with skid plates. I may have a wrong part. Not-really-optional tools are left as optional. What could have taken an hour took almost 3 with frequent trips to get additional tools and re-re-reading the instructions. The saving graces are that this is the same sturdy material as my skid plate and the fasteners are both hard to get to and an unusual type.
To install the Millercat shield on a Tundra with the TRD Pro skid plate:
- Assemble the main shield and side plates before starting
- Chock the rear tires (on the rear side), jack up the vehicle from the lift point on the skid plate and support the vehicle with jack stands or adequate platforms under the tires. The jack will need to be removed from the lift point.
- Insert the provided rivnuts in the holes indicated in the print instructions, in the rear-facing side of the rear crossmember
- Remove the 17mm bolts from the tow hooks and set all that hardware aside
- Loosen the 12mm bolts at the front of the plate about 1/4 inch. Do not remove.
- Fully loosen the 5mm hex bolt at the lift point
- Remove the long 12mm bolts from the sides of the skid plate
- *Carefully* fully loosen the 15mm bolts at the rear of the skid plate. At this point the plate should drop enough that the entire bolt has come through the crossmember. Watch your head.
- Use pliers to hold the retaining washer and unscrew the 15mm bolt. Set the bolt, washers and nuts aside for later use. You will not need to reuse the tube sleeves if you have them.
- Tighten the 5mm hex bolt on the skid plate lift point, leaving about 1/4 inch of the bolt showing
- Replace the long 12mm bolts on either side of the skid plate, leaving them slightly loose
- Slip the front end of the cat shield over the rear end of the skid plate; the shield should be between the skid plate and crossmember. The skid plate will support the front of the shield.
- Align the rear of the shield with the holes in the rear crossmember and attach with long M8 bolts and the provided nuts
- Fasten the two smaller security bolts to the rivnuts in the rear-facing side of the rear crossmember
- Reuse the long 15mm skid plate bolts to sandwich the skid plate and shield to the front crossmember
- I had to hold the washers between my fingers, contort my hand, drop the washer on the “up” side of the skid plate, turn my hand over, retrieve the washer then place it over the end of the bolt. Repeat with the nut.
- I strongly recommend using a bottle jack and some wood spacers to help hold the plates up while you’re fiddling with the fasteners. There should be a jack under your rear passenger seat if you haven’t already found it.
- Tighten all 12mm bolts, the 5mm hex bolt and replace the tow hooks using the 17mm bolts