Question about a 94' Infiniti Q45?

autozone and advance will chk ur codes but u still need it repaired,i go to dealer or good auto shop pay a little more get it fixed rite first time most good shops will chk codes for fee and rite it off if they repair car,then hopefully its done rite the first time,idle control vale replaced idle control screw on carburated cars but fuel inj added new an xciting parts to fuel del system,ha