This is the Alliant Power AP63593, a new aftertreatment fuel injector for the 2017 to 2022 GM 6.6L Duramax L5P in the Chevy Silverado and GMC Sierra 2500HD and 3500HD. GM calls it the indirect fuel injector, or the low pressure diesel hydrocarbon injector. It replaces GM 12717296 and the older 12641278, and it crosses to Standard Motor Products FJ1379. GM uses the same injector number on the 2.8L Duramax LWN in the Chevy Colorado and GMC Canyon, and this part is listed for those trucks for 2017 to 2019. This is not one of the eight engine injectors.

This is an emissions part for the factory exhaust system. It sprays a small amount of diesel into the exhaust so the particulate filter can burn itself clean. When it sticks, leaks or clogs, regenerations fail, the soot load climbs and the truck sets exhaust aftertreatment fuel injector codes. Check the feed line, the wiring and the connector before you replace it, and fix any exhaust leak at the injector seat.

Specifications

Fits / Applications

• 2017-2022 Chevrolet Silverado 2500HD and 3500HD, 6.6L Duramax L5P
• 2017-2022 GMC Sierra 2500HD and 3500HD, 6.6L Duramax L5P
• 2017-2019 Chevrolet Colorado and GMC Canyon, 2.8L Duramax LWN (GM lists the same injector number for 2016 to 2022, confirm by VIN)
• 2023 and newer 6.6L trucks: GM lists the same injector number, confirm by VIN
• For the factory exhaust aftertreatment system. One per vehicle.

Let the exhaust cool before you start. Clean the seat in the exhaust, fit a new gasket or seal where the truck uses one, torque to the GM figures and check the fuel feed line for leaks. Clear the codes and run a service regeneration with a scan tool to confirm the repair.

Part Numbers & Cross Reference

Alliant Power AP63593  ·  GM 12717296  ·  GM, older number 12641278  ·  Standard Motor Products FJ1379

Cross-reference numbers can change with engine serial, build year and emissions tier, so treat this list as a starting point. Send us your engine serial number and we will confirm the exact match against your build before anything ships. That check is free and takes a few minutes.

Frequently Asked Questions

Which trucks does the AP63593 fit?

2017 to 2022 Chevy Silverado and GMC Sierra 2500HD and 3500HD with the 6.6L Duramax L5P. It is also listed for the 2017 to 2019 Colorado and Canyon with the 2.8L Duramax. For those, and for a 2023 or newer 6.6L truck, call 530-668-0818 with your VIN.

What GM numbers does the AP63593 replace?

GM 12717296 and the older 12641278 that it took over from. It also crosses to Standard Motor Products FJ1379.

Is this one of the engine injectors?

No. It is the single injector in the exhaust system that doses fuel for particulate filter regeneration. GM lists it as the indirect or hydrocarbon fuel injector.

Will it fit my 2011 to 2016 LML?

No. GM lists a different injector for the LML and the LGH vans, and that one is AP63592. Call 530-668-0818 with your VIN if you are not sure which one you have.

Why Buy From Valley Fuel Injection

We are a diesel fuel-injection and turbocharger shop in Woodland, CA, rebuilding pumps, injectors and turbos on our own benches since 1993, not a drop-ship storefront. When you call, you talk to the people who test these units. We verify fitment against your engine serial, VIN or build date before anything ships, so the right part arrives the first time.

Not sure the injectors are the problem? We test and diagnose in-house before you buy. See our common rail injector testing and rebuild service.