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Cummins X15 SCR 2018-2021: OEM 4394835

CUMMINS X15 SCR 2018-2021: OEM 4394835

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$4,995.00

AVAILABILITY IN STOCK
OEM NUMBER4394835
PART TYPESCR
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPEX15
YEAR2018-2021
PART NUMBER4394835
APPLICATION NOTESPACCAR, 485-565, EPA17

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx SCR, Tamerx part number 4394835 ( OEM Part Number 4394835 ). 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 X15, production years 2018-2021, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

OEM NUMBERS

Primary OEM4394835
Additional OEM4394835

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490551985
WEIGHT75.00 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.


Engineered for demanding road conditions, the Cummins X15 SCR 2018–2021: OEM 4394835 helps your engine stay compliant while maintaining dependable operation. This genuine SCR unit is designed to reduce NOx emissions efficiently, supporting cleaner exhaust and consistent performance. Manufactured to meet OEM specifications, it ensures proper fitment and long-lasting durability in heavy-duty applications. Count on a reliable solution that keeps your X15 running cleaner and ready for every mile ahead.

FITMENT CHART

YEARMAKEENGINE(S)
2018Cummins X15
2019Cummins X15
2020Cummins X15
2021Cummins X15

PEOPLE ALSO ASKS | BLOG(S)

Keeping your truck’s emission aftertreatment system operating smoothly is essential to meet environmental standards and avoid costly service interruptions. The Cummins X15 SCR 2018–2021: OEM 4394835 is a key Selective Catalytic Reduction (SCR) component designed to lower harmful nitrogen oxides (NOx) in diesel exhaust. Focusing on how this SCR unit supports system reliability can help truck owners and maintenance teams make smarter decisions for everyday operation.

  • Engineered specifically for Cummins X15 engines from 2018 to 2021, the OEM 4394835 SCR unit integrates precisely into your truck’s emission control system.

  • The SCR (Selective Catalytic Reduction) system works by injecting diesel exhaust fluid (DEF) into the exhaust stream, where a chemical reaction converts NOx into harmless nitrogen and water vapor.

  • Using the genuine OEM 4394835 SCR ensures accurate compatibility with your engine’s emission management controls, reducing the chances of diagnostic trouble codes or warning lights.

  • Proper SCR function supports consistent DEF dosing, which helps maintain effective NOx reduction while minimizing unnecessary DEF consumption.

  • A reliable SCR unit contributes to smoother communication between emission sensors and the engine control module, helping avoid false fault signals that can disrupt daily operation.

  • Regular inspection of the SCR and related components can catch early signs of wear or contamination before they lead to emission system issues.

  • Built to meet Cummins’ original manufacturing standards, this SCR module withstands heat and vibration typical of everyday highway and regional use.

  • Easy installation makes it a practical choice for maintenance technicians and fleet service crews during routine emission system servicing.

Choosing the Cummins X15 SCR 2018–2021: OEM 4394835 from Tamerx Diesel Parts means equipping your emission control system with a quality, engine-specific component. With the right SCR unit in place and regular system attention, you’ll help keep your truck emission-compliant, dependable, and ready for the road ahead.

The Selective Catalytic Reduction (SCR) system is engineered to provide long-term emissions control in modern diesel engines. Designed to handle high exhaust temperatures and continuous use, the SCR catalyst is built for durability. While there is no exact expiration date, its lifespan can vary depending on maintenance, operating conditions, and overall engine health.

  • In many diesel applications, the SCR catalyst can last several hundred thousand miles under normal operating conditions.

  • Consistent use of clean, manufacturer-approved Diesel Exhaust Fluid (DEF) helps prevent contamination and supports long-term efficiency.

  • Engine problems such as excessive oil consumption or coolant leaks can significantly shorten SCR lifespan by damaging the catalyst internally.

  • Unresolved Diesel Particulate Filter (DPF) issues may increase exhaust heat or soot exposure, placing added stress on the SCR.

  • Severe-duty operation, heavy loads, or extended idling can gradually impact aftertreatment components over time.

  • Prompt attention to warning lights and fault codes can prevent minor issues from turning into permanent catalyst damage.

While the SCR system is designed for extended service life, proper maintenance and early problem detection are key to maximizing its durability. Keeping the engine in good condition and maintaining the entire emissions system helps ensure the SCR performs reliably for many miles.

When the SCR isn’t functioning, the vehicle can show emissions warnings, experience reduced performance, or enter a protective derate mode. These responses help protect engine systems and emissions compliance.

A poorly functioning SCR may indirectly impact combustion balance and system efficiency, which can slightly increase fuel usage. Maintaining emissions components helps keep fuel economy stable.

Signs include dashboard emissions alerts, DEF system warnings, or recurring diagnostic codes after scans. These indicators suggest the SCR or supporting sensors may need inspection.

Contaminated or low-quality DEF can interfere with the conversion reaction and reduce SCR effectiveness. This often results in reduced emissions performance and possible fault codes.

Cummins SCRs