I bought my 2012 FX2 super cab in January 2015 with 36,000 miles on it. I knew when I bought it that it would need them soon so just last week I put on a set of 4 Cooper Discoverer HT Plus tires. Great tires, they look great, made in the USA and feel awesome! Also the truck needed front rotors since I was getting a bad shimmy. Got a set of rotors and pads from RockAuto and put them on last week, wow what a difference!!! Then when I was driving over the weekend in some heavy rain, trying to get on the interstate the truck fell flat on its face, check engine light came on and was flashing, I pedaled the truck on the gas then off on and then of trying to not get run over and it picked up enough to get in the right lane out of the way. The all great P0300 code came up for misfire, my MPG went down about 5mpg and had sputtering at WOT especially around 4500-5000 rpm. So yesterday I changed the plugs on it with Motorcraft SP534's with the gap at .030 and holy crap did the truck wake up!!!! It felt like I had a shot of nitrous on the dang thing when I took it for a test drive lol. Old plugs didn't look too bad with a light brown burn to them. So the check engine light is still on last night and when I plug the reader in, P0300 is gone and I get code P0430 Catalyst System Efficiency Below Threshold Bank 2. I cleared the code this morning on my way into work so when I get home tonight I'll see how it looks then. My MPG is back up to normal again too. Just wondering if I blew out my catalytic converter or O2 sensor when I had the misfire? Its the 3.5L 3.73 rear with no tune (yet) and all stock everything.