GMC Repair: 98 GMC backfire/misfire 5.7, filter air, time post

Question
Hello-first time post, I'm somewhat mech inclined. I have a 5.7L GMC K1500 and at low speeds it backfire's. I'm thinking it is getting to much gas and I have no idea how to correct this.

Answer
Hi
I would recommend a major tune up )Plugs, wires, cap, rotor, fuel filter, air filter, throttle body clean and injector flush)
I would then recheck.
If this engine is getting too much fuel, it woulod USUALLY set a code, and turn on the Service Engine Soon light.
I hope this helps.
Good luck
Pawl