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Cummins B6.7, L9 DOC Filter 2018-2021: OEM 4394859

CUMMINS B6.7, L9 DOC FILTER 2018-2021: OEM 4394859

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$2,495.00

CORE CHARGE:

$1,000.00
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 NUMBER4394859
PART TYPEDOC Filter
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPEB6.7, L9
YEAR2018-2021
PART NUMBER102-0154RM-DOC-6
APPLICATION NOTESE-ONE, 200-320, EPA17
ADDITIONAL NOTESInlet Catalyst

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx DOC Filter, Tamerx part number 102-0154RM-DOC-6 ( OEM Part Number 4394859 ). 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

Additional Notes: Inlet Catalyst

OEM NUMBERS

Primary OEM4394859
Additional OEM4394859

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490549647
WEIGHT35.00 LBS

SHIPPING OPTIONS

Ship Weight : 35.00 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.


Designed to fit 2018–2021 Cummins B6.7 and L9 engines, the OEM 4394859 DOC Filter is an essential component for maintaining proper exhaust aftertreatment operation and emissions compliance. This Diesel Oxidation Catalyst (DOC) helps convert harmful exhaust gases into less harmful substances before they pass through the remaining aftertreatment system. Manufactured to original equipment standards, it delivers precise fitment and seamless integration with factory sensors and mounting hardware. Its heavy-duty construction is built to withstand high exhaust temperatures and the demanding conditions of commercial truck applications. As a direct OEM replacement, this Cummins B6.7 and L9 DOC Filter supports consistent system function while helping reduce the risk of costly downtime. Tamerx Diesel Products LLC provides quality diesel aftertreatment components that align with strict manufacturer specifications.

FITMENT CHART

YEARMAKEENGINE(S)
2018Cummins B6.7 L9
2019Cummins B6.7 L9
2020Cummins B6.7 L9
2021Cummins B6.7 L9

PEOPLE ALSO ASKS | BLOG(S)

Understanding the internal structure of the Cummins B6.7, L9 DOC Filter 2018–2021 (OEM 4394859) helps explain how this critical aftertreatment component functions. As a Diesel Oxidation Catalyst (DOC), this unit is engineered to treat exhaust gases before they reach the DPF and SCR system.

At the core of the assembly is a catalyst system designed to manage high exhaust temperatures while maintaining steady flow. The internal and external components work together to ensure proper emissions treatment and durability in heavy-duty applications.

Key Components of OEM 4394859

  • Catalyst substrate
    • A honeycomb-style ceramic or metallic structure that maximizes surface area for exhaust contact.
  • Precious metal washcoat
    • Typically platinum and/or palladium, which initiate oxidation reactions.
  • Stainless steel housing
    • A durable outer shell built to withstand heat and vibration.
  • Connection flanges
    • Mounting points that integrate the DOC into the exhaust system.
  • Gaskets and clamps
    • Sealing hardware that prevents exhaust leaks during installation.
  • Sensor ports
    • Openings for temperature or oxygen sensors that communicate with the ECM.

Each of these components plays a specific role in allowing the DOC to convert carbon monoxide and hydrocarbons into less harmful gases. When properly installed and maintained, the OEM 4394859 unit supports consistent exhaust treatment and protects downstream aftertreatment components in 2018–2021 Cummins B6.7 and L9 engines.

Keeping your DOC (Diesel Oxidation Catalyst) filter in good condition starts with proper engine care and consistent maintenance. Since the DOC works directly with exhaust gases, anything that disrupts combustion or introduces contaminants can shorten its service life.

Preventative habits go a long way in reducing buildup and internal damage.

To help your DOC filter last longer:

  • Use high-quality diesel fuel to minimize residue
  • Stay current on oil changes with manufacturer-approved fluids
  • Repair faulty injectors as soon as symptoms appear
  • Fix oil or coolant leaks immediately
  • Avoid excessive idling whenever possible
  • Address check engine or emissions warning lights promptly

Driving patterns also matter. Frequent short trips that never allow the engine to reach normal operating temperature can contribute to soot accumulation. Allowing the vehicle to reach and maintain proper exhaust temperatures helps keep the catalyst cleaner.

Routine inspections of sensors and exhaust components can also prevent minor issues from turning into major repairs.

By staying proactive and correcting small problems early, you can reduce the risk of premature DOC filter failure and avoid unnecessary downtime.

It provides a controlled passage where oxidation reactions occur to condition exhaust before further treatment.

Yes, it works in conjunction with components like the DPF and SCR to manage exhaust emissions effectively.

Aftertreatment system warnings or exhaust flow irregularities can suggest the DOC filter needs inspection.

This DOC filter helps convert exhaust hydrocarbons and carbon monoxide into less harmful compounds within the exhaust stream.

Cummins DOC Filters