Does trouble code mean automatic check engine light on?

[92470]

I have an 87' V10 and when I turn the ignition switch on, the check engine comes on briefly like is supposed to. My question is if my truck had registered a trouble code, would my light automatically come on? When first started, it idles rough and the motor really shakes. It also surges, like it's trying to breath, but it has never died. If you gently give it gas, it really starts to sputter until you put your foot into it a bit. After you drive it, it really idles and drives pretty decent.
Vaccumm lines look good, EGR is fine, new plugs, wires, cap, rotor. No light, but I'm convinced something is not right. Just wondering if it did register a code, would my light have to go on. Thanks