My 89 SE has developed a hestation or surging feeling at cruising speed. Obviously something is wrong. However, the check engine has never come on.

So the question is, will the computer give a code if the check engine light does not come on?

 

Yes it will. My knock sensor was bad for a few months and it never triggered the CEL, but when I'd have it hooked up to the computer where I have my oil changed they could see all the codes that the computer had thrown since it was last reset. I would have the codes pulled to see what it says.