Check Engine light

I was wondering if anybody can tell me how to check the code that my check engine light is throwing....I cant figure out what plug to use... Thanks any help would be great....

At 60K miles, 80K, 120K, etc., the Malfunction Indicator Light will come on, supposedly so you get dealer to check emissions but more likely so they can try to sell you a timing belt replacement. By the way, do get the timing belt replaced every 60K miles, and maybe get the water pump changed at the 120K point along with it, as it's an internal water pump, behind the timing belt, and mine started leaking at that point, so it's a big labor savings $$$ to do both at once. The Malfunction Indicator Light is re-set by swapping a wire push-on connector under the dash, driver side, right next to the firewall; it's hard to see, lie down and look up, there will be a bare connector, just swap it, then swap back next time the light goes on at that set interval.
Swap the Brown/white stripe and the green wires.
See

I am actually trying to see if my truck is throwing a code cause it has been running like crap

Theres a green wire on the passenger fender well, ground that, then turn your key on (not start) light will flash. I think it's a green wire.