2004 Toyota Avalon misses badly

Misses bad for a few seconds at about 50 miles and up.
126000 miles on car change spark plugs, Air filter, oil has always been change at $5000 miles or lower. Change fuel filter. No check engine light on.

When was the last time the spark plug wires were changed?

I’m pretty sure this 2004 Avalon has coil-on-plug ignition

If there’s no Check Engine light, then what you feel might not be a miss, but instead torque converter clutch shudder.

When was the last time the transmission fluid/filter was serviced?

Tester