The only problem with your post is that the fix for the CEL/MIL depends on the code that accompanies the light. Many of the things you talk about are for the remedy of a lean condition, and there are two codes that come up for that, P0171 and P0174.
These are two codes out of several hundred. So, the best advice when the Check Engine Light comes on is to pull codes and go from there. It is almost always a bad idea to blindly aim your shotgun under the hood and start wrenching on whatever you hit.