Fuel Injectors for 2001–2017 GMC Sierra 1500

How long do injectors last in a GMC Sierra 1500?

Expect 100,000 to 150,000 miles on the 4.8L and 5.3L Vortec engines. The 6.0L and 6.2L often go longer—sometimes 180,000—because they run richer under load. Flex-fuel models wearing E85 regularly tend to fail earlier, around 90,000 miles, due to ethanol's corrosive effect on seals. If you tow heavy or idle extensively, injectors wear faster from constant heat cycling.

Can I replace Sierra 1500 injectors myself?

On the 4.8L and 5.3L, it's straightforward—upper intake plenum comes off, fuel rail unbolts, injectors pull straight out. Plan two hours if you've done it before. The 6.0L and 6.2L have tighter engine bays, especially in crew cabs. You'll need a fuel pressure gauge, injector puller, and new O-rings. Depressurize the fuel system first. If you've never done a fuel rail, have a shop handle it—one crossed connector and you're chasing a fire hazard.

What are the most common injector symptoms on these V8s?

Lean codes P0171/P0174 show up first when injectors start clogging. You'll feel hesitation between 1,500 and 2,500 RPM. AFM engines (2007-up 5.3L) develop cylinder-specific misfires when injectors can't keep up during mode transitions. Hard starts in cold weather point to weak spray pattern. If you see black smoke and smell raw fuel, one or more injectors are stuck open—that's a pull-the-plugs-and-replace situation.

Do AFM engines have special injector issues?

Yes. The 2007-2014 5.3L with Active Fuel Management cycles between V8 and V4 mode constantly. Injectors on cylinders 1, 4, 6, and 7 work harder during four-cylinder operation, leading to uneven wear. You'll see P0300 random misfires or P0171 lean codes when AFM injectors can't deliver enough fuel during reactivation. Some techs disable AFM to extend injector life, but that requires a tune. If you're replacing injectors on an AFM engine, do all eight—don't mix old and new.