Cummins B6.7, L9 SCR 2018-2021: OEM 5418491
CUMMINS B6.7, L9 SCR 2018-2021: OEM 5418491
ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured Tamerx SCR, Tamerx part number 5418491RM-SCR-2 ( OEM Part Number 5418491 ). All parts are proudly remanufactured in the U.S.A. to the highest of OEM standards, and improvements are often applied to the original design in the remanufacturing process. This part is primarily made for a Cummins B6.7, L9, production years 2018-2021, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
OEM NUMBERS
| Primary OEM | 5418491 |
| Additional OEM | 5418491 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490552371 |
| WEIGHT | 75.00 LBS |
SHIPPING OPTIONS
Ship Weight : 75.00 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 2018–2021 Cummins B6.7 and L9 diesel applications, the SCR unit with OEM 5418491 is a key part of the exhaust aftertreatment system. This selective catalytic reduction module is engineered to match the exhaust layout and emissions sensor locations specific to both B6.7 and L9 engines, ensuring proper integration with factory diesel exhaust fluid (DEF) delivery and control systems. Its function is to work with DEF to help reduce nitrogen oxide (NOₓ) emissions in the exhaust stream, supporting compliance with applicable emissions standards for these model years. Reliable SCR operation helps maintain consistent exhaust flow and contributes to the effective performance of downstream aftertreatment components. This page provides application-focused details to assist with identifying the Cummins B6.7 & L9 SCR 2018–2021 (OEM 5418491) for service and replacement needs.
FITMENT CHART
| YEAR | MAKE | ENGINE(S) | ||||
|---|---|---|---|---|---|---|
| 2018 | Cummins | B6.7 | L9 | |||
| 2019 | Cummins | B6.7 | L9 | |||
| 2020 | Cummins | B6.7 | L9 | |||
| 2021 | Cummins | B6.7 | L9 | |||
PEOPLE ALSO ASKS | BLOG(S)
The Cummins B6.7 and L9 SCR, OEM 5418491, works as part of the engine’s Selective Catalytic Reduction (SCR) aftertreatment system to reduce nitrogen oxide (NOx) emissions before exhaust gases leave the vehicle. Rather than trapping particles, this system relies on a controlled chemical reaction to treat regulated exhaust gases.
- Step 1: Exhaust flows through the aftertreatment system
- After combustion, exhaust gases move through the emissions system. By the time exhaust reaches the SCR stage, it contains NOx that must be treated to meet emissions requirements.
- Step 2: DEF is injected upstream
- The system injects Diesel Exhaust Fluid (DEF) into the exhaust stream before it reaches the SCR unit. DEF is a urea-based fluid designed specifically for SCR systems.
- Step 3: DEF breaks down into ammonia
- As DEF mixes with hot exhaust gases, it breaks down into ammonia, which is required for the SCR reaction.
- Step 4: SCR catalyst converts NOx
- Inside the SCR catalyst (OEM 5418491), exhaust passes through a catalyst-coated structure. Ammonia reacts with NOx and converts it into:
- Nitrogen (N₂)
- Water vapor (H₂O)
- Inside the SCR catalyst (OEM 5418491), exhaust passes through a catalyst-coated structure. Ammonia reacts with NOx and converts it into:
- Step 5: Sensors regulate efficiency
- Temperature and NOx sensors monitor conditions before and after the SCR. The engine control module uses this data to adjust DEF dosing and confirm the system is operating correctly.
The Cummins SCR (OEM 5418491) works by using DEF and catalyst chemistry to convert NOx into safer exhaust gases, supporting emissions compliance and stable aftertreatment operation for 2018–2021 Cummins B6.7 and L9 engines.
The signs of a bad SCR (Selective Catalytic Reduction) system usually show up as emissions warnings, NOx efficiency problems, and operating restrictions. Because the SCR’s role is to reduce NOx using DEF, failure is typically detected by the vehicle’s control system rather than through obvious mechanical symptoms.
Common signs of a bad SCR
- Check engine light or emissions warning
- Often the first indicator that the SCR is no longer meeting emissions requirements.
- NOx efficiency fault codes
- Codes such as SCR efficiency below threshold or NOx conversion low strongly suggest the SCR catalyst is contaminated or degraded.
- Repeated derate or restricted mode
- Many vehicles limit speed or engine operation when SCR faults persist to stay emissions-compliant.
- Abnormal DEF behavior
- Increased DEF usage, DEF dosing errors, or DEF system warnings may occur as the system tries to compensate.
- Strong ammonia smell
- If DEF is injected but not properly converted, ammonia can pass through the exhaust and create a sharp odor.
- DEF crystallization or visible deposits
- White, crusty buildup near the doser/injector or SCR inlet often accompanies SCR failure.
- SCR-related faults return after repairs
- If NOx sensors, DEF dosing components, and wiring are confirmed good but SCR faults keep returning, the SCR catalyst itself is likely failing.
A bad SCR is most often identified by persistent NOx efficiency codes, repeated derate conditions, abnormal DEF behavior, and recurring emissions warnings. When these signs are consistent, replacement is typically the most reliable solution.
Yes, problems with the SCR catalyst can lead to aftertreatment warning indicators and diagnostic fault codes.
NOx sensors and exhaust temperature sensors monitor conditions around the SCR catalyst to help assess conversion effectiveness.
Yes, OEM 5418491 is a genuine Cummins outlet catalyst module designed for this aftertreatment application.
Yes, the outlet catalyst module can typically be serviced or replaced separately from the rest of the aftertreatment system.
Cummins SCRs
