Misfire on a Pull
Our Town Car has been great for 260,000 miles with upkeep along the way. It has now developed a slight but irritating missfire between 40 and 60 mph on a pull at light throttle. It shows no codes. I had a real mechanic test for codes with his Snap-On reader; no codes. I had a good transmission man convinced that the original trans finally needed a rebuild but when he drove it he said the trans was good; it is a missfire. I replaced the fuel filter and 2 coils with questionable boots. 5 coils have been replaced. What do I try next?