Off the top of my head I would say the Protege, that being said, I'm not sure "whats harder" is the way I would phrase it. Different setup, different tools, different technique. The tensioner on the Protege is mechanical / spring loaded whereas the Tacoma ( I'm assuming it was a V6 3.4L engine ) is a hydraulic setup. Also, you have a dual overhead cam setup on the Mazda and only a single on the Toyota. All in all, if you handled the Tacoma without too much difficulty, I don't see why you couldn't pull off the Protege, although I don't recommend any DIY'ers performing any such task. Get the proper service information and read over it before making the attempt, let me know if you have any particular, slightly more specific questions about the job.