Gm 3.8L misfire - fuel or electrical

My 3.8L hesitates a couple times a week. It only happens when I am cruising at 45 MPH/1500 RPM. It lasts only a second. Accelerating makes it go away.

It never happens during acceleration, only cruising. I got the check engine light for a misfire on cylinder 4 only after it had been hesitating for a few weeks. It backfired the time the light went on.

I put new wires and plugs on my 3.8L three years/20,000 miles ago when I had a hesitation/misfire problem. That fixed it then. My original plugs/wires were at 95,000 miles.

I have never put in a fuel filter for 10 years, 115,000 miles.

Does this sound like an electrical or a fuel problem?

It seems like the plugs/wires should be OK after only three years.

I can probably do a fuel filter if that is a likely cause. I’ve replaced fuel filters before and it never has been a problem.

Weak spark tends to cause misfire first under hard acceleration and/or high engine speeds. Does this engine have multiple fuel injectors? It could be a dirty injector. I would replace the fuel filter and put a bottle of Techron in the gas tank.