02 grand Marquis hesitation/miss

My Merc has a hesitation/miss between 30-60 mph. it happens more uphill or under a load unless you pour on the gas then it goes away. I don't notice it above 60 or so. I replaced the plugs a year ago. boots also. no codes. let me know what you think.

It might be torque converter clutch slip. How is the transmission fluid level and quality? Is it a bright red or is it tired and brownish? Does it smell burnt?

It might be torque converter clutch slip. How is the transmission fluid level and quality? Is it a bright red or is it tired and brownish? Does it smell burnt?

the tranny fluid seems fine it's been replaced in the past couple years. it feel like it could be vacuum. or maybe a sensor that's not tripping a code.

Try a new Fuel, Air filters, and clean the MAF/IACT sensors.

Try a new Fuel, Air filters, and clean the MAF/IACT sensors.

It ended up being the coil pack on number 4. it fianlly want bad enough to throw a code.
now it runs like a new one.