major tune up for 97 tahoe LS

well i would do plugs ,wires, cap and rotor and coil, and also a new fuel filter. i had # 5 always throwing codes i did all that and she runs like a dream. now i did a new distributor cause i broke the tabs off the old one. but your lookin at around 200-250 dep. on the brand but stay with ac delco plugs. i have 174000 on my 98 and she runs beautiful. i doubt its an injector. but try some seafoam or chevron fuel cleaner. good luck. any other ? just ask

Start by checking spark plug,compression and fuel injector on #4 Cylinder.