
Cummins ISL9 DOC
CUMMINS ISL9 DOC

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a New, Skyline Emissions DOC, Skyline Emissions part number LJ0426-M. This part is primarily made for a Cummins ISL9, and comes with a One Million Miles or One Year Warranty.
OEM NUMBERS
| Additional OEM | 4353289, 4353289NX, 4353289RX, 4387170, 4387170NX, 5287368, 5287368NX, 5300556, 5300556NX, 5308482, 5308482NX, A035H109, A041R626, A043T214, A047V489, A052A785 |
ADDITIONAL DETAILS
| CONDITION | New |
| UPC / Barcode | 00840490549302 |
| WEIGHT | 36.80 LBS |
SHIPPING OPTIONS
Ship Weight : 36.80 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.
WARRANTY
SELLER warrants the Products to be free from defects in material or workmanship according to the SELLER’s warranty policy as stated in the Product’s owner’s manual. SELLER will only warrant product if conditions as determined in the Product’s owner’s manual are adhered to. SELLER’s warranty will not apply if Product replacement is required because of accident, neglect, misuse, transportation or other causes outside of SELLER’s control. All regular freight shipping costs will be paid by SELLER unless the Product is found upon inspection by SELLER not be to eligible for replacement under this warranty, in which case the CUSTOMER shall be responsible for the shipping costs. Expedited freight charges shall be the sole responsibility of the CUSTOMER. THE FOREGOING WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
LIMITATION ON PRODUCT AND INSTALLATION WARRANTY LIABILITY
SELLER WILL NOT BE LIABLE FOR ANY LOSS, DAMAGE, OR EXPENSE, INCLUDING INJURY OR DAMAGE TO BUSINESS, EARNINGS, PROFITS OR GOODWILL SUFFERED BY ANY PERSON INCLUDING DISTRIBUTOR AND ITS CUSTOMERS, CAUSED DIRECTLY OR INDIRECTLY BY THE IMPROPER PRODUCT INSTALLATION OR MAINTENANCE SERVICE BY DISTRIBUTOR OR CUSTOMER, AND/OR VEHICLE/PRODUCT ACCIDENT, NEGLECT, MISUSE, COMPONENT SWAPPING, IMPROPER USE OF ALTERNATIVE FUELS OR FUEL ADDITIVES, TRANSPORTATION OR OTHER CAUSES OUTSIDE OF SELLER’S CONTROL PURSUANT TO THE PRODUCT’S OWNER’S MANUAL; AND IN NO EVENT WILL SELLER BE LIABLE FOR ANY DAMAGES, HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, FOR ANY COSTS OF PROCUREMENT OF SUBSTITUTE GOODS, FOR ANY CONSEQUENTIAL, SPECIAL, INDIRECT OR INCIDENTAL DAMAGES, OR FOR PENALTIES SUFFERED BY DISTRIBUTOR, ITS CUSTOMERS OR ANY OTHER PARTY DUE TO IMPROPER PRODUCT INSTALLATION OR MAINTENANCE SERVICE BY DISTRIBUTOR OR CUSTOMER, AND/OR VEHICLE/PRODUCT ACCIDENT, NEGLECT, MISUSE, COMPONENT SWAPPING, IMPROPER USE OF ALTERNATIVE FUELS OR FUEL ADDITIVES, TRANSPORTATION OR OTHER CAUSES OUTSIDE OF SELLER’S CONTROL PURSUANT TO THE PRODUCT OWNER’S MANUAL, EVEN IF SELLER WILL HAVE BEEN ADVISED OF THE POSSIBILITY OF SAME. THIS LIMITATION IS INTENDED TO LIMIT THE LIABILITY OF SELLER AND WILL APPLY NOTWITHSTANDING ANY FAILURE OF ESSENTIAL PURPOSE OF ANY LIMITED REMEDY. SKYLINE® DOC AND DPF PARTS CARRY A LIMITED WARRANTY OF 3 YEARS, SENSORS CARRY A LIMITED WARRANTY OF 1 YEAR. COMPONENTS THAT ARE SUBJECT TO REGULAR USAGE WEAR AND TEAR ARE NOT COVERED UNDER THE STANDARD SELLER PRODUCT WARRANTY, THESE COMPONENTS INCLUDE BRACKETS, RUBBER COMPONENTS, GASKETS, SEALS, NUTS, BOLTS AND WASHERS. No loss or damage to the Products or any portion thereof shall relieve the Customer from its obligations hereunder.
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.
Installed in Cummins ISL9 engines, this diesel oxidation catalyst (DOC) is designed to treat exhaust gases as part of the factory aftertreatment system. The DOC supports the reduction of hydrocarbons and carbon monoxide before exhaust flows to downstream components. Manufactured to OEM specifications, it ensures proper fitment and compatibility with the engine’s exhaust configuration. Constructed from durable materials, it is suited for the high-temperature conditions common in medium- and heavy-duty diesel applications. This component is a dependable option for fleet maintenance and targeted repair needs requiring consistent aftertreatment system operation.
PEOPLE ALSO ASKS | BLOG(S)
The main cause of DOC (Diesel Oxidation Catalyst) failure is contamination from unburned fuel or engine oil, which poisons or coats the catalyst substrate and reduces its oxidation efficiency. The DOC relies on clean exhaust flow to properly oxidize hydrocarbons (HC) and carbon monoxide (CO). When contamination occurs, the catalyst can no longer generate the heat required for proper emissions control and DPF regeneration.
Fuel contamination is commonly caused by leaking or over-fueling injectors, incomplete combustion, or repeated failed regeneration events. Excess fuel entering the exhaust can overheat the DOC, leading to thermal cracking or melting of the substrate. Oil contamination from turbo seal leaks, excessive oil consumption, or worn engine components can coat the catalyst surface and permanently reduce its effectiveness.
Midway through diagnosis, the most common contributing factors to DOC failure include:
- Leaking or malfunctioning fuel injectors
- Excessive oil consumption or turbo seal leaks
- Repeated failed regeneration events
- Overheating from high exhaust temperatures
- Sulfur or fuel contamination
- Poor engine air-fuel control
In most cases, the DOC does not fail from normal wear. It fails because upstream engine or fuel system issues were not corrected. Proper injector maintenance, oil control, and early diagnosis of regeneration problems are essential to preventing DOC failure and avoiding costly aftertreatment repairs.
Yes, a failing DOC can lead to abnormal sensor readings and trigger emissions-related diagnostic codes.
Yes, it can be inspected and replaced by a professional if it’s damaged or no longer functioning correctly.
Yes, it operates in coordination with exhaust sensors to support emissions monitoring by the engine control module.
Heavy-duty trucks, buses, and commercial equipment equipped with Cummins ISL9 engines use this DOC.




























































