check engine & trac lights on after checking spark plugs

I changed my oil today and was thinking of doing a tune up, so I pulled the first spark plug to see how they looked. The truck has almost 80,000 miles, so I figure is about time. I plan on picking up new plugs tomorrow so I put everything back together and fired her up. Everything seems fine except now the check engine light and the trac light is on. What the hell did I do?

 

Unless they looked rough, I'm not sure you need to change them either. Unless they are different the 2013s are a 100K or 120K change in that engine.

 

I checked 3 times just to be sure, the only thing I unplugged was the coil on the first cylinder. It runs and sounds fine, there's an advanced auto right down the road, I'll use their code reader tomorrow. The truck is fairly new to me, and it's close enough to the 100k mark for me, plus I read from a few people on here they gained some MPG from switching to NGK plugs. I just wanna tinker, and of course something always breaks, so is my luck. Thanks guys

 

Nope

Yup

My wife's '12 Highlander suggests 200k on the plug change.

 

Yup. 2TR-FE, at least in the 13 is 120 because they are Iridum not copper.