02 Rendezvous missing - Injector?

I have a 02 Rendezvous with 161,000 miles on it. It has developed a slight miss when ideling. I changed the plugs and wires around 105,000 miles. I did have a code "misfire on cylinder 2" recently but it hasn't shown for nearly a month now. But the miss is still there. I did run the injector cleaner additive to the gas tank but that didn't help.

What is the life expectancy of an injector? Am I throwing away money by trying to really clean them or better to just replace them.

It isn't burning oil and is still getting 21 on the hwy. Was getting 24 a couple of years ago.

Any thoughts?

THanks...