Description

Cummins 4394695 Inlet Catalyst Module - Genuine Cummins Diesel Oxidation Catalyst

The Cummins 4394695 is a genuine Cummins inlet catalyst module, the first catalyst in the aftertreatment assembly. Inlet Catalyst Module is Cummins' own name for the Diesel Oxidation Catalyst. It oxidizes hydrocarbons and carbon monoxide in the exhaust and generates the heat needed for DPF regeneration.

Key Functions:

- Oxidizes hydrocarbons and carbon monoxide ahead of the DPF
- Burns dosing fuel during active regeneration to raise exhaust temperature
- First stage of the aftertreatment assembly

Fitment & Specifications:

- Engines: Cummins ISC 8.3L, ISL / L9 8.9L
- Emissions: EPA17
- Position: Inlet module, first catalyst in the aftertreatment assembly

Verify fitment with us before ordering to ensure the correct part for your application.

Purpose of the Part

The 4394695 sits ahead of the DPF and oxidizes hydrocarbons and carbon monoxide in the exhaust. During active regeneration it burns the fuel delivered by the dosing injector to raise exhaust temperature high enough for the DPF to burn off accumulated soot.

Issue Symptoms / When to Replace

- Failed or repeating regens, rising DPF differential pressure, aftertreatment derate. Physically: plugged or damaged inlet face, cracked substrate, exhaust leaks at the joints.
- A plugged inlet catalyst usually has an upstream cause - dosing injector, turbo seals, fuel injectors. Fix that first or the replacement plugs too.

Brand Information

Cummins has built diesel engines since 1919 and is one of the largest independent engine manufacturers in the world. Its Cummins Emission Solutions division builds complete aftertreatment systems, with the catalyst engineered as a matched set alongside the DPF and SCR behind it.

Installation Notes

Inspect the DPF behind it before closing up. A catalyst that failed from fuel or oil contamination has almost certainly loaded the filter, and a new catalyst in front of a plugged DPF buys nothing.

How to Identify an OEM Part

Cummins logo and Cummins part number tag on the housing. Confirm the number matches 4394695. Suffix RX indicates a Cummins remanufactured exchange unit; new units carry no suffix.

Why Buy 4394695 from Wisent Parts

  • ⏱️
    Fast shipping
    Orders before 12PM EST ship same business day.
  • 🛡️
    180-day warranty
    All parts covered from delivery date.
  • ↩️
    Easy returns
    30-day returns.
  • ✅
    Verify fitment
    Send VIN/ESN and we’ll confirm.

Shop with confidence

Warranty & Return Information
Warranty Information

Wisent Parts offers a 180-day warranty on all parts from the date of delivery. This warranty covers orders placed directly through our website. If a part fails during this period, we’re here to help - whether it’s a replacement, repair, or refund. For full details, refer to the Warranty page.

Return Information

Wisent Parts accepts returns within 30 days of delivery. All returns are subject to a restocking fee. To qualify, parts must be unused and in their original condition. For full return instructions and restocking fee details, please refer to the Returns page.