
Cummins QSB 6.7L, 4.5L NOx Sensor 2018-2024: OEM 5491422
CUMMINS QSB 6.7L, 4.5L NOX SENSOR 2018-2024: OEM 5491422

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Genuine New, Cummins NOx Sensor, Cummins part number 5491423OE ( OEM Part Number 5491422 ).This part is primarily made for a Cummins QSB 6.7L, 4.5L, production years 2018-2024, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
OEM NUMBERS
| Primary OEM | 5491422 |
| Additional OEM | 5491422 |
ADDITIONAL DETAILS
| CONDITION | Genuine New |
| UPC / Barcode | 00840490552784 |
| WEIGHT | 1.00 LBS |
SHIPPING OPTIONS
Ship Weight : 1.00 LBS
UPS Ground, 2nd Day Air, Next Day Air
SHIPPING POLICY
Tamerx Diesel Products ships via UPS Ground. Next day air shipping can be arranged for a reasonable price of anywhere from $50.00 - $100.00 depending on the weight of the product and your location. We will do everything we can to make sure that you get the service you need. We understand how important it is to receive your order as quickly as possible.
In most cases Tamerx Diesel Products only needs one address, as long as your product is shipping to the same location as your billing information. In order to eliminate credit card fraud, your billing information must match the credit card you provide.
The terms, conditions, and details of our warranty vary from product to product. Specific warranty details can be found below.
Tamerx Diesel Products provides a replacement warranty on all of our parts. The duration and mileage limitations of the warranty vary by product and are specified on the product's detail page/item listing.
Please note that the warranty covers replacement of the part and the cost of shipping the replacement part to you only. It does not cover any shop, labor, towing, or any similar or related costs. This is not a "money back guarantee".
If you experience a problem with your part or it is not functioning properly, the correct warranty procedure is to call us at (510) 257-1777 (8:00 AM - 5:00 PM ET Monday through Friday). Be sure to have your order number and/or other relevant order information ready so we can easily locate your order and resolve your issue as quickly as possible. From that point, we will review with you any troubleshooting steps that may need to be taken and other areas or systems that can be checked to rule out external problems contributing to your part's issue. If a replacement is determined to be necessary, we will then arrange for your replacement part to ship out ASAP and issue any necessary return shipping labels and/or documents.
As is the case for the majority of the diesel products sold on Tamerx Diesel Products, your part's warranty is active as soon as you install it. In some other cases, warranty activation is contingent upon you sending us your core (i.e., your old part). Tamerx Diesel Products will provide you a return shipping label for parts that have a warranty with a core return condition. When we have received your core return, the part's warranty coverage begins. We reserve the right to void the product warranty if your core is not received within the allotted time, or if it isn't received at all. If the warranty for the diesel part you are purchasing has a core return requirement, it will be clearly noted on the product detail page/item listing.
What is a Core Charge?
A core charge (also called "core deposit") is similar to the deposit you might pay for a can or bottle of soda and is a standard requirement in the auto parts industry. For example, in many states, to promote recycling, you pay a deposit when you purchase a can of soda and receive your deposit back when you return the empty can. Many automotive parts have a core charge, or core price, that works in essentially the same way as a soda can deposit.
30 Day Core Charge Hold
You authorize Tamerx Diesel Products, to hold your credit card for the specified core charge amount and that you agree to return your core with 30 days of receiving the purchased part. When we have received your core return, the hold is released and the core charge payment is canceled.
The customer, or parts buyer, is responsible for any shipping costs associated with core returns unless otherwise specified in the product listing/detail page. Tamerx Diesel Products offers prepaid UPS shipping labels (SKU numbers UPS-CR1 and UPS-CR2) for use in returning your core that are available for purchase on our website during your shopping/order process.
The shipping label you will need to use for the core return is dependent upon what part you are purchasing. UPS-CR1 is good for cores weighing up to 20 pounds. UPS-CR2 is appropriate for shipping cores weighing 21 pounds or more. You must include enough information with the core return that clearly identifies it as a.) a Core Return, and b.) contains enough information we can use to clearly associate the core return with your order. Including a copy of the invoice or packing slip that came with the original shipment, clearly marked "Core Return", is ideal. Alternately, you can include a note marked as "Core Return" that includes your order number, full name and address, and phone number or other contact information. Failure to include this information with your returned core will most likely delay any due core credit being issued and/or delay any applicable warranty activation. Core returns need to be for the exact part purchased and cannot be damaged. Substituting another part in place of the part you have purchased is not acceptable.
All fluids must be drained.
If you have purchased a set or a parts package, you will need to return cores for all components of the set. For example, if you have purchaed a high pressure oil pump with an IPR valve, you will need to return both HPOP and IPR valve cores to receive proper credit. If you have purchased an EGR cooler/EGR valve package, your core return must consist of an EGR cooler core and an EGR valve core, or core credit will not be given.
Core Charges are often mandated by state legislature, and, as such, the actual core charge and taxes on the charge may vary depending on the state in which you buy your part. The Tamerx Diesel Products core charge presented to you online today with your item is representative of the most common core charge.
Covering 2018–2024 Cummins QSB 6.7L and 4.5L applications, the NOx Sensor with OEM 5491422 is a vital part of the emissions aftertreatment system. This sensor monitors nitrogen oxide (NOₓ) levels in the exhaust stream and sends that data to the engine control module (ECM), enabling precise control of diesel exhaust fluid (DEF) dosing and SCR system adjustments. Accurate NOx readings help the ECM maintain emissions compliance and optimize aftertreatment performance across varying operating conditions. Reliable sensor operation can also help reduce the likelihood of emissions-related warning lights or diagnostic fault codes. This page provides application-specific details to assist with identifying the Cummins QSB 6.7L & 4.5L NOx Sensor 2018–2024 (OEM 5491422) for service and replacement needs.
FITMENT CHART
| YEAR | MAKE | ENGINE(S) | ||||
|---|---|---|---|---|---|---|
| 2018 | Cummins | QSB 6.7L | 4.5L | |||
| 2019 | Cummins | QSB 6.7L | 4.5L | |||
| 2020 | Cummins | QSB 6.7L | 4.5L | |||
| 2021 | Cummins | QSB 6.7L | 4.5L | |||
| 2022 | Cummins | QSB 6.7L | 4.5L | |||
| 2023 | Cummins | QSB 6.7L | 4.5L | |||
| 2024 | Cummins | QSB 6.7L | 4.5L | |||
PEOPLE ALSO ASKS | BLOG(S)
The Cummins NOx Sensor, OEM 5491422, is an emissions monitoring sensor used on Cummins QSB 6.7L and QSB 4.5L engines in 2018–2024 applications. Its main purpose is to measure nitrogen oxide (NOx) levels in the exhaust stream and send that information to the engine control module (ECM).
NOx sensors are essential for engines equipped with SCR (Selective Catalytic Reduction) aftertreatment systems. The ECM uses NOx sensor readings to confirm that the SCR system is working correctly and to help manage DEF dosing so emissions stay within regulated limits.
What the NOx sensor does
- Detects NOx concentration in exhaust gases
- Sends real-time emissions data to the ECM
- Helps control DEF dosing accuracy
- Supports SCR efficiency monitoring
- Helps trigger warning lights or fault codes when emissions are out of range
OEM 5491422 is a key sensor that helps Cummins QSB 6.7L and 4.5L engines maintain proper emissions control and aftertreatment operation from 2018 to 2024.
No, a NOx sensor should not be reused after professional servicing, and the recommended solution is replacement.
A NOx sensor is a precision electronic emissions component. When it starts failing, the issue is usually internal—such as sensor element degradation, contamination, moisture intrusion, wiring damage, or electrical drift. Professional servicing may clean the outside or connector, but it cannot restore accurate NOx readings or long-term reliability.
Why reusing a serviced NOx sensor is not recommended
- Recurring NOx sensor fault codes
- Incorrect NOx readings
- SCR efficiency faults returning
- Derate / restricted mode
- Short and unpredictable remaining service life
Even if it works temporarily, the sensor often fails again soon and triggers repeat SCR and DEF system issues.
No—NOx sensors should not be reused after servicing. For dependable emissions monitoring and stable SCR operation, replacement is the correct recommendation.
Recurring aftertreatment warnings and abnormal NOx readings suggest the sensor may need replacement.
It provides real-time NOx data so the engine control unit can regulate DEF dosing and conversion.
Yes, NOx sensor problems can lead to broader aftertreatment diagnostic codes.
Technicians should inspect wiring, connections, and sensor condition.




































