Bosch 0445120255 New OEM Injector - 03-04 Dodge Ram 5.9L Cummins

The Bosch 0445120255 is a brand-new OEM common rail fuel injector for 2003 to early 2004 Dodge Ram 2500 and 3500 trucks with the 5.9L ISB Cummins and CPL 8213, 8228, or 8412. This all-new Bosch injector uses no reused components, requires no core return, and is backed by a 12-month unlimited-mileage warranty. Sold individually; order a quantity of six for a full set.

New vs Reman: The Right Call for Your 03-04 5.9L

The 0445120255 and the 0986435503 reman fit the exact same 2003 to early 2004 5.9L Cummins application. The difference is condition, core requirement, and the starting point of every component inside. Buy the 0445120255 if you want a true factory-new injector with no used parts and no core return. Choose the 0986435503 reman if budget is the primary driver and a Bosch-remanufactured unit fits your plan. Confirm your CPL, then this is the right injector to order.

5.9L Cummins Injector Failure Symptoms

Owners of 2003 to early 2004 Dodge Ram 5.9L Cummins trucks commonly search for injector replacement after experiencing ticking or knocking at idle, rough or uneven idle, hard starts, low power, white or black smoke, and declining fuel economy. On the 3rd gen 5.9L common rail platform, injector degradation is most often tied to fuel contamination or the cumulative effects of high-pressure common rail cycling over time. The Bosch 0445120255 restores factory spray pattern, atomization, and fuel metering when a confirmed failed injector is the source of these conditions.

Why This Injector Stands Out

Brand-new OEM injectors for the 03-04 5.9L common rail are harder to source than most buyers expect - the majority of the market is remanufactured units. The 0445120255 is built entirely new by Bosch, not rebuilt from a core, so every precision surface, nozzle, solenoid, and control valve starts fresh. Bosch manufactures these with the latest engineering updates, which means the 0445120255 is manufactured to Bosch's current OE specifications for this application.

Every injector is completely end-of-line tested using OE test equipment and OE specifications before leaving the facility. The result is a direct-fit replacement that restores factory fuel delivery without calibration, tuning, or modification.

What Comes in the Box

• (1) New Bosch common rail fuel injector - 0445120255
• (1) Nozzle washer
• (1) Injector seal O-ring

Order a quantity of six for a complete set. Connector tubes and valve cover gasket are not included. At a minimum, replace the connector tube O-rings (F00RJ01571) at the time of installation. For the most complete service and best protection against future leaks, replacing the full connector tubes (F00RJ01572) is strongly recommended.

Bosch 0445120255 Fitment Coverage

Fits 2003 to early 2004 Dodge Ram 2500 and 3500 with the 5.9L ISB Cummins. CPL required: 8213, 8228, or 8412. Your engine dataplate will show one of those CPL codes along with the rated horsepower - most trucks in this range are tagged at 305hp, though some early 2003 trucks were rated at 250hp and use the same injector. Verify CPL before ordering regardless of the hp rating shown.

• 2003 to early 2004 Dodge Ram 2500 - 5.9L ISB Cummins (305hp)
• 2003 to early 2004 Dodge Ram 3500 - 5.9L ISB Cummins (305hp)
• Early 2003 Dodge Ram 2500 / 3500 - 5.9L ISB Cummins (250hp) - verify CPL matches 8213, 8228, or 8412

Does not fit 2004.5-2007 applications (325hp, CPL 8346/8347/8350/8351). Those trucks use the 0445120238 new or the 0986435505 reman.

Cross Reference Numbers for 0445120255

If your existing injector carries any of the numbers below, the Bosch 0445120255 is the confirmed direct replacement - verify CPL matches 8213, 8228, or 8412 before ordering.

• Bosch: 0445120255, 0445120210, 0445120113, 0445120018, 0986435503
• Cummins / Mopar: 3947550, 3949619, 3949913, 4940589, 5254686, 5263318, R8004082AA, R8310748AA

Avoid These Common Mistakes

• Ordering without checking CPL. The 03 to early 04 5.9L uses CPL 8213, 8228, or 8412. If your CPL falls outside those codes, verify before ordering. CPL is stamped on the engine dataplate.
• Assuming 2004 model year means early-build fitment. The mid-year changeover creates two different injector applications inside one model year. CPL is more reliable than calendar year alone.
• Skipping the connector tube service. At minimum replace the connector tube O-rings at the time of installation. Leaking connector tubes are the most common source of post-install fuel system issues on this platform - replacing the full connector tubes is strongly recommended.
• Ordering one when six are needed. This listing is priced per injector. Order a quantity of six for a complete set on the 5.9L ISB.

Final Check Before You Order

• Engine CPL confirmed as 8213, 8228, or 8412
• Model confirmed as 2003 or early 2004 Ram 2500 or 3500
• Quantity set to six if replacing a full set
• Connector tube O-rings or full connector tubes sourced for installation

For an all-new OEM injector on a 2003 to early 2004 Dodge Ram 5.9L Cummins with no core return required, the Bosch 0445120255 is the correct part to order.

Frequently Asked Questions