Cummins ISB 6.7L SCR Outlet Catalyst Module 2018-2022: OEM 4394691
CUMMINS ISB 6.7L SCR OUTLET CATALYST MODULE 2018-2022: OEM 4394691
ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured Tamerx SCR Outlet Catalyst Module, Tamerx part number 4394691RM-SCR ( OEM Part Number 4394691 ). 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 ISB 6.7L, production years 2018-2022, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
OEM NUMBERS
| Primary OEM | 4394691 |
| Additional OEM | 4394691 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490556867 |
| WEIGHT | 78.00 LBS |
SHIPPING OPTIONS
Ship Weight : 78.00 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.
Supporting reliable exhaust aftertreatment performance, the Cummins ISB 6.7L SCR Outlet Catalyst Module (2018–2022) OEM 4394691 is a vital component for maintaining proper emissions system operation. Manufactured to meet original equipment specifications, it ensures precise compatibility with Cummins ISB 6.7L engines across the specified model years. This SCR outlet catalyst module serves as the final stage of the selective catalytic reduction system, helping reduce nitrogen oxide (NOx) emissions before exhaust gases are released while supporting compliance with emissions standards. Constructed from durable, high-quality materials, it is engineered to withstand high exhaust temperatures and the demanding conditions of heavy-duty diesel applications. Ideal for fleet operators, technicians, and maintenance professionals, this OEM SCR outlet catalyst module helps maintain dependable aftertreatment system functionality and long-term reliability.
FITMENT CHART
| YEAR | MAKE | ENGINE(S) | ||||
|---|---|---|---|---|---|---|
| 2018 | Cummins | ISB 6.7L | ||||
| 2019 | Cummins | ISB 6.7L | ||||
| 2020 | Cummins | ISB 6.7L | ||||
| 2021 | Cummins | ISB 6.7L | ||||
| 2022 | Cummins | ISB 6.7L | ||||
PEOPLE ALSO ASKS | BLOG(S)
The Cummins ISB 6.7L SCR Outlet Catalyst Module (OEM 4394691) is a critical aftertreatment component designed for 2018–2022 Cummins ISB 6.7L engines. Installed near the end of the exhaust system, this Selective Catalytic Reduction (SCR) Outlet Catalyst Module helps reduce harmful nitrogen oxide (NOx) emissions after Diesel Exhaust Fluid (DEF) has been injected into the exhaust stream. Working together with the Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), and DEF system, it plays a key role in helping the engine meet modern diesel emissions standards.
Unlike the DPF, which captures soot, the SCR Outlet Catalyst Module is specifically designed to convert NOx emissions into harmless nitrogen and water vapor through a catalytic chemical reaction.
What Does the Cummins 4394691 SCR Outlet Catalyst Module Do?
- Reduces nitrogen oxide (NOx) emissions
- The catalyst reacts with ammonia produced from DEF to convert harmful NOx gases into harmless nitrogen and water vapor.
- Completes the emissions treatment process
- Positioned at the outlet of the SCR system, it performs one of the final stages of exhaust cleaning before gases exit the exhaust system.
- Works with the DEF system
- The module relies on accurately metered DEF to create the chemical reaction required for efficient NOx reduction.
- Supports the complete aftertreatment system
- It operates alongside the DOC, DPF, NOx sensors, temperature sensors, and the Engine Control Module (ECM) to maintain efficient emissions control.
- Maintains proper exhaust flow
- Its design allows treated exhaust gases to move smoothly through the final stage of the aftertreatment system.
- Helps maintain emissions compliance
- A properly functioning SCR Outlet Catalyst Module is essential for meeting diesel emissions regulations and supporting reliable engine operation.
The Cummins ISB 6.7L SCR Outlet Catalyst Module (OEM 4394691) serves as the final stage of the engine's emissions-control process. By converting harmful NOx emissions into harmless nitrogen and water vapor, it helps produce cleaner exhaust, supports the efficiency of the complete aftertreatment system, and contributes to the long-term reliability of compatible Cummins ISB 6.7L engines.
While your vehicle may still be drivable when the SCR Outlet Catalyst Module is failing, it is not recommended to continue driving for an extended period. A failing SCR Outlet Catalyst Module can reduce the effectiveness of the emissions system, trigger warning lights, and eventually cause the engine to enter a reduced-power mode.
Addressing the problem early can help prevent additional damage to the aftertreatment system and avoid costly repairs.
Here are some of the risks of continuing to drive with a failing SCR Outlet Catalyst Module:
- Engine derate or reduced-power mode
- Many diesel engines automatically limit engine performance when the SCR system detects a serious emissions fault.
- Recurring check engine light
- The engine control module may continuously trigger warning lights and store SCR-related fault codes until the issue is repaired.
- Reduced NOx conversion efficiency
- A failing catalyst module cannot effectively reduce nitrogen oxide (NOx) emissions, causing the SCR system to operate below its intended performance.
- Higher DEF consumption
- The emissions system may use more Diesel Exhaust Fluid (DEF) than normal as it attempts to compensate for reduced catalyst efficiency.
- Additional aftertreatment system stress
- Continuing to drive with an unresolved SCR issue can place extra strain on components such as the NOx sensors, DEF injector, temperature sensors, and other parts of the emissions system.
- Failed emissions inspections
- A malfunctioning SCR Outlet Catalyst Module may prevent the vehicle or equipment from meeting emissions standards, resulting in failed inspections where required.
If your vehicle is showing SCR-related warning lights, recurring fault codes, or has entered a reduced-power mode, it's best to have the system inspected as soon as possible. Driving a short distance to a repair facility is generally acceptable, but delaying repairs can increase downtime and lead to more extensive aftertreatment system damage.
The module is engineered for continuous heavy-duty operation under high exhaust temperatures, engine vibration, repeated thermal cycling, and demanding commercial driving conditions.
Technicians commonly inspect the module when diagnosing SCR efficiency fault codes, elevated NOx readings, emissions warning lights, reduced aftertreatment efficiency, excessive exhaust restriction, or visible damage to the catalyst housing.
Yes. DEF contamination, excessive soot, engine oil contamination, coolant intrusion, or catalyst poisoning can reduce SCR efficiency and negatively affect emissions performance.
Yes. The OEM 4394691 is manufactured to Cummins specifications, providing direct compatibility with the original exhaust routing, mounting locations, and aftertreatment system configuration.
Cummins SCR Outlet Catalyst Modules
