Check all the areas you were in. Look for vacuum hoses that are broken or bad. Any obvious electrical items unplugged or bad.
Most likely I think you bumped something or unplugged something. If all you did was add the resistor and then remove it, that shouldn't cause a need for plugs/wires. It also shouldn't allow the PCM to adjust that much and cause this type of issue.
Please change the title of this post. All caps/with no description or hint of the possible issue is not going to help you draw the attention of people with experience on your problem. A suggestion would be "Poor Idle/Running"