Never towed a travel trailer, have you? As far as sag, you need a properly adjusted WDH, even though it’s only 3k lbs. as far as performance and mileage, you are dragging a huge sail through the air at highway speeds. Your mileage will drop to less than half, and top gears will be useless...
No payment here. I’m not old, not young. I see both sides, but today people expect everything because “I work hard for it”. I bought my first house in 1999. It was old, orange Formica countertops, gold refrigerator, 800 sq ft. In order to afford this, I drove a $500 car which would rain bits of...
I agree, it makes no sense, especially when the 4Runner has the wiring, but is rated to tow less. Any competent trailer shop should be able to install a controller, but sounds like your Bluetooth unit is working well for you.
You can wire in your p3 with the generic harness it came with.
https://www.tacoma4g.com/forum/threads/brake-controller-harness-install-diy-how-to-instructions.6777/
Have you read this thread? The wires are not there. Did you read the other thread? The 4R manual shows a prewire. The Tacoma manual does not. This information is readily available. There is a write up on how to install one floating around.