Description
The PAI 050778 is an aftermarket nitrogen-oxide (NOx) sensor that replaces Cummins 2894940 (and the 2894940RX reman) on the SCR aftertreatment of EPA10/EPA13 ISB 6.7L and ISL engines. M20×1.5 thread with high-temperature anti-seize, 4-pin rectangular connector, 23.5 in lead with sensor module. Replacement clears NOx-conversion fault codes and restores SCR closed-loop control.
Signs You Need a New NOx Sensor
- Active SCR efficiency or NOx conversion fault codes (SPN 4364, 3216, 3226, etc.)
- “DEF Fluid Quality” / “Aftertreatment” warning lamp and engine derate
- NOx-sensor heater-circuit codes after restart
- Sensor body or wiring harness physically damaged or corroded
- NOx-sensor electrical-circuit fault codes that don’t clear with key cycle
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 050778 |
| Part Type | NOx Sensor |
| Engine Compatibility | Cummins ISB 6.7L, ISL (EPA10 / EPA13) |
| Thread | M20 × 1.5 (with anti-seize) |
| Pin Count | 4 |
| Connector Shape | Rectangular |
| Probe Length | 3.67 in |
| Lead Length | 23.5 in |
| Color / Finish | Black / Silver |
Cross References
This NOx sensor replaces or is equivalent to the following part numbers:
- Cummins: 2894940, 2894940RX, RX2894940, 2871979, 4984577, 4954222
Applications
Fits Cummins SCR aftertreatment on the following engine families:
- Cummins ISB 6.7L (EPA10 / EPA13, on-highway 2010–2016)
- Cummins ISL 8.9L (EPA10 / EPA13)
Representative trucks and equipment using these engines:
- Freightliner M2 106, Cascadia day cab, Sprinter chassis with ISB
- Kenworth T370, T440, T470 with ISL
- Peterbilt 337, 348 with ISL
- School and transit buses (Blue Bird, Thomas, IC Bus) with ISB or ISL
- RV chassis (Freightliner XC, Spartan K2/K3) with ISB or ISL
NOx sensors are sensitive to silicone, RTV, and unburned fuel — do not handle the sensing tip and verify the upstream DPF/SCR is healthy before installing. Verify your Cummins ESN, CPL, and exact sensor location (turbo outlet vs. SCR outlet) before ordering.
