Is replaacing a charcoal canister on a 98 4runner 4cyl really necessary?

It may be if you want a check engine light to go off or if you need to pass emissions. Otherwise, it shouldn't damage anything by not changing it. DONT keep topping off gas tank at the gas station!! Once that handle clicks off, dont try squeezing in a bit more or try to round it off to the nearest dollar. One click and done. When you try to put in more gas after it clicks off, you actually force gas into the vent of the gas tank which leads to the canister. Then you end up with liquid fuel in the charcoal VENT canister where there is electrical valve, and then you saturate the canister with fuel when it is designed for fuel vapor fumes. 281,000 miles on my 1998 4Runner limited V6 and runs like new.

Thank you for the information, I talked to an honest mech. and he said the same thing.

Is this Toyota still available