Paccar MX-13 Injectors — EPA10, EPA13, EPA17 & EPA21 Covered

The Paccar MX-13 is the 12.9L heavy-duty engine that powers a huge share of the modern Kenworth and Peterbilt Class 8 fleet, and its fuel injectors are one of the most critical and most frequently replaced service items on the engine. HD Injectors’ remanufactured Paccar MX-13 injectors are rebuilt on genuine OEM cores and restored to factory flow specifications, giving fleets and owner-operators a cost-effective alternative to new OEM pricing. We stock MX-13 injectors for every major EPA emissions variant in North America including EPA10, EPA13, EPA17, and EPA21, so whether you’re running a 2011 T660 or a current-model T680, we have the right part number for your truck.

Find the Right MX-13 Injector by EPA Variant

MX-13 injectors are not cross-compatible across EPA emissions tiers. Part numbers, calibration specs, internal geometry, and ECM programming all differ between variants, so it’s critical to match the injector to your engine’s specific emissions certification. Here’s how the four MX-13 generations break down:

Paccar MX-13 EPA10 Injector (2010–2012)

EPA10 was the first emissions tier for the MX-13 in North America, introduced with SCR aftertreatment. These injectors fit 2010–2012 Kenworth T660, T680, T700, T800, W900, and Peterbilt 386, 387, 388, 389, 579, and 587 tractors. Shop Paccar MX-13 EPA10 injectors →

Paccar MX-13 EPA13 Injector (2013–2016)

EPA13 introduced updates to meet 2013 U.S. EPA greenhouse gas and fuel economy standards, with revisions to the fuel system and aftertreatment. EPA13 MX-13 injectors fit 2013–2016 Kenworth T680, T880, W900, and Peterbilt 579, 567, and 389 tractors. Shop Paccar MX-13 EPA13 injectors →

Paccar MX-13 EPA17 Injector (2017–2020)

EPA17 brought updated calibration, improved fuel economy, and revised aftertreatment hardware compared to EPA13. EPA17 injectors fit 2017–2020 Kenworth T680, T880, W990, and Peterbilt 579, 567, and 389 tractors. Shop Paccar MX-13 EPA17 injectors →

Paccar MX-13 EPA21 Injector (2021–Present)

EPA21 is the current-generation MX-13 configuration, delivering further fuel efficiency gains and emissions refinements on 2021 and newer trucks. EPA21 injectors fit current-production Kenworth T680, T880, W990, and Peterbilt 579, 567, and 389 tractors. Shop Paccar MX-13 EPA21 injectors →

Why Choose for Paccar MX-13 Fuel Injector Replacement

• Budget-friendly alternative to new OEM MX-13 injectors across every EPA tier
• Eliminate engine knocking from worn nozzles and failing internals
• Reduce exhaust smoke and keep DPF regens on schedule
• Regain lost fuel economy — critical for per-mile operating cost on Class 8 tractors
• OEM-spec calibration and flow data tagged on every remanufactured unit

Paccar MX-13 Injector Rebuild Process

Every MX-13 injector we ship, regardless of EPA variant, is fully disassembled, ultrasonically cleaned, and inspected for wear. Nozzles, springs, seals, and other high-wear components are replaced with OEM-spec parts. Each unit is then flow-tested across the full operating pressure range, high-pressure leak-tested, and calibration-verified before packaging. Calibration data ships with every injector so your technician can program the ECM correctly during installation.

Not Sure Which MX-13 Injector You Need?

Shop Paccar MX-13 injectors by EPA variant using the links above or browse our full MX-13 catalog to see every in-stock part number. If you’re not certain which EPA tier your engine is, or you want to verify the correct MX-13 part number before ordering, fill out our Make Sure It Fits form with your VIN and engine serial number. Our team will cross-reference your truck, confirm your emissions tier, and identify the exact MX-13 injector part number you need before your order ships. No guesswork, no wrong-part returns.

MX-13 Injector FAQs