Fuel Injectors for 2001–2017 GMC Yukon

How long do injectors last in a Yukon with the 5.3L V8?

The LM7 and LC9 5.3L engines typically see injector degradation between 130,000-170,000 miles. Flex-fuel versions wear faster due to ethanol's solvent properties attacking seals and spray baskets. Towing heavy loads regularly accelerates wear by another 20,000 miles. If you're running E85 more than occasionally, expect to replace injectors closer to 110,000 miles. Highway-driven units last longer than city stop-and-go vehicles.

Can I replace Yukon injectors myself or does this need a shop?

The 5.3L and 6.0L have injectors under the intake plenum on older Vortec engines, meaning you pull the doghouse cover inside or work from underneath. Gen IV engines (2007+) have side-mount injectors accessible after removing the fuel rails. It's a 4-6 hour job if you've done intake work before. You'll need a fuel pressure release procedure and injector puller for stuck O-rings. Shops charge 3-5 hours labor depending on engine access.

What diagnostic steps confirm bad injectors versus other issues?

Start with fuel trims at idle and 2500 RPM. If long-term trims exceed ±10%, test injector resistance (12-16 ohms cold). A noid light shows pulse, but doesn't confirm spray pattern. Pull injectors and send them for flow testing, or swap suspect injectors between cylinders and see if the misfire code follows. P0300 random misfire with multiple cylinders misfiring points to fuel delivery, not ignition. Scan live data for injector pulse width—if one cylinder shows 30% different pulse than others, that injector is clogged or leaking.

Why do Yukons throw lean codes on one bank but run rich on the other?

The GMT900 platform has a known issue with uneven carbon buildup between banks due to PCV flow bias. Bank 1 (passenger side) often runs leaner because injectors clog faster from intake valve deposits redirecting airflow. The ECM compensates by richening Bank 2, which eventually throws P0172 or P0175. This creates a situation where fuel trims are maxed in opposite directions. Replacing all eight injectors at once prevents this imbalance from recurring within 30,000 miles.