New to forum and not much of a mechanic and followed post about my civic running rough poor gas mileage and putting a new throttle control sensor would solve problem. Sounded logical. It didn't help so I pulled spark plug wires off one at a time to see if I had a bad wire. The third wire was covered in oil and not firing. Car had been sitting for two years and evidently the oil cover gasket dried out and oil leaked into plug cavity. Hope this helps someone solve a problem.

 

Welcome to the forum. thank You for the post. Good to pass on experience to others.