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Cummins X15 Decomposition Reactor Tube 2018-2024: OEM 5418122

CUMMINS X15 DECOMPOSITION REACTOR TUBE 2018-2024: OEM 5418122

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$1,850.00

CORE CHARGE:

$250.00
iCORE DISCLAIMER: The CORE charge is a 30 day hold and will not be processed as long as the CORE is returned within 30 days. If you do not have a CORE or fail to return the CORE within 30 days, the CORE charge hold amount will be processed at that time.

AVAILABILITY IN STOCK
OEM NUMBER5418122
PART TYPEDecomposition Reactor Tube
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPEX15
YEAR2018-2024
PART NUMBER5418122RM

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx Decomposition Reactor Tube, Tamerx part number 5418122RM ( OEM Part Number 5418122 ). 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 2018-2024, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

OEM NUMBERS

Primary OEM5418122
Additional OEM4394654, 5417855, 5418122, 705313AT, A058S619, A062R554

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490547964
WEIGHT18.00 LBS

SHIPPING OPTIONS

Ship Weight : 18.00 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.


Step up your emissions game with the Cummins X15 Decomposition Reactor Tube 2018–2024 – OEM 5418122, engineered to support cleaner exhaust and satisfy emissions standards. This critical component helps break down soot and particulates for smoother exhaust flow and better aftertreatment performance. Built to precise OEM specs for a reliable fit and long-lasting durability, it’s the upgrade your Cummins needs to stay compliant and efficient. Keep your rig running cleaner and stronger mile after mile.

FITMENT CHART

YEARMAKEENGINE(S)
2018Cummins X15
2019Cummins X15
2020Cummins X15
2021Cummins X15
2022Cummins X15
2023Cummins X15
2024Cummins X15

PEOPLE ALSO ASKS | BLOG(S)

Modern diesel engines rely on advanced emissions systems to reduce harmful exhaust emissions, and the Cummins X15 Decomposition Reactor Tube (2018–2024, OEM 5418122) is a key part of that process. This reactor tube works within the aftertreatment system to help break down DEF (diesel exhaust fluid) and support the conversion of nitrogen oxides (NOx) into harmless components. Choosing the correct OEM-grade reactor tube helps ensure your emissions system operates as designed, supporting cleaner exhaust and reliable engine performance.

This decomposition reactor tube plays an important role in emissions control — here’s why it matters:

  • Aids DEF Breakdown – Helps properly mix and decompose DEF in the exhaust stream, which is critical for effective Selective Catalytic Reduction (SCR) operation.

  • Supports NOx Conversion – By ensuring DEF is correctly introduced and decomposed, the reactor tube helps the SCR catalyst more efficiently convert nitrogen oxides into safe, inert gases.

  • Maintains Emissions Efficiency – Proper reactor tube performance helps the emissions system maintain optimal efficiency, reducing the likelihood of emissions-related warnings or derates.

  • OEM-Grade Fit and Durability – As OEM 5418122, this component meets original specifications for fit, materials, and thermal performance, ensuring dependable long-term function.

  • Prevents Aftertreatment Issues – A worn or malfunctioning reactor tube can lead to improper DEF distribution, higher NOx levels, or inefficient SCR performance — replacing it helps avoid these problems.

A failing or inefficient decomposition reactor tube can compromise emissions performance, lead to increased exhaust pollutants, or cause the engine to enter restricted operation modes. The Cummins X15 Decomposition Reactor Tube (OEM 5418122) delivers the OEM-standard quality and performance needed to support your engine’s emissions system and keep it working smoothly. For customers seeking a trusted replacement part, Tamerx offers high-quality components engineered to help maintain long-lasting emissions control and dependable engine operation.

The decomposition reactor tube is a key component in the diesel aftertreatment system, helping break down diesel exhaust fluid (DEF) before it enters the SCR catalyst. Because it operates in high-temperature exhaust conditions, regular inspection helps ensure proper DEF dosing and emissions system reliability.

  • Inspection during routine service: The reactor tube should be visually inspected during scheduled exhaust or emissions system maintenance.

  • Check when fault codes appear: SCR- or DEF-related warning lights may indicate issues that warrant immediate inspection.

  • Monitor for buildup or blockage: Crystallized DEF or soot deposits can restrict flow and affect system performance.

  • Inspect after DEF quality issues: Contaminated or incorrect DEF can increase the risk of internal deposits.

  • Evaluate during exhaust component repairs: Any time upstream or downstream aftertreatment parts are serviced, the reactor tube should be checked.

  • Replacement is condition-based: Reactor tubes are typically replaced only when damage, blockage, or severe contamination is found.

The decomposition reactor tube does not follow a strict service interval, but regular inspections help prevent costly SCR system problems. Staying attentive to warning signs and including it in routine exhaust checks supports proper emissions control and long-term system reliability.

Yes, factors such as contaminated fuel, poor maintenance, or excessive heat cycles can accelerate wear. Attention to routine servicing helps mitigate premature failure.

Unusual exhaust odors, increased emissions output, or emission-system warning lights can signal problems. These issues suggest the tube may not be breaking down exhaust byproducts as intended.

While its primary role is emissions control, a malfunctioning reactor tube can indirectly impact engine efficiency and throttle response. Keeping this part in good condition helps maintain overall system balance.

Under normal operating conditions, this component is built for long service life, but actual longevity varies with usage and maintenance. Regular system checks help ensure it continues functioning properly.

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