A brake controller isn't a vehicle-specific item, you can install a brake controller on just about any vehicle. The 1998 Toyota 4Runner wasn't prewired for a brake controller, so you'll need to hardwire the controller.
You'll begin by installing a functional 4 pole trailer connector (if you don't have one already) which accesses the vehicle's taillight circuits for use by the trailer. I'd recommend using part # 118341. To install the # TK90160 Tekonsha Primus brake controller, you'd use... view full answer...