2131536 | Genuine Paccar® DOC Module, Inlet Catalyst

Description: A Diesel Oxidation Catalyst (DOC) 2131536 - also known as the inlet module in an aftertreatment system - is the first major emissions control component in a diesel exhaust system. It treats exhaust gases before they reach the Diesel Particulate Filter (DPF) or Selective Catalytic Reduction (SCR) system. DOC Module, Inlet Catalyst MX-13, EPA21, work condition, used take-off Kenworth T880 2024 Part Number: 2131536 Condition: Take Off Manufacture/Brand: Paccar Fits 2131536 For PACCAR / MX‑13 engines in Kenworth / Peterbilt trucks Purpose of using 2131536: 1. Reduce Harmful Emissions Oxidizes (chemically reacts with) pollutants in the exhaust: Carbon Monoxide (CO) → Carbon Dioxide (CO₂) Unburned Hydrocarbons (HC) → Water (H₂O) + CO₂ Soluble organic fraction (SOF) of soot → burned off 2. Increase Exhaust Temperature The oxidation reaction inside the DOC heats the exhaust. This increased temperature helps ignite and burn soot in the DPF, supporting regeneration. 3. Prepare Exhaust for Next Stage Acts as a pre-treatment stage before gases reach the: DPF (which traps soot) SCR (Selective Catalytic Reduction, which reduces NOx) 4. Help Meet Emission Regulations Without the DOC, a diesel engine would emit illegal levels of CO and HC. It's required to comply with EPA, CARB, Euro VI, and similar emissions standards. Signs of a Bad DOC Module, Inlet Catalyst 2131536: 1. Check Engine Light (CEL) or Emissions Warning Triggered by fault codes such as: DOC efficiency below threshold Exhaust temp too low High soot load in DPF Codes: P0420, P244A, SPN 3251, SPN 3242 (varies by make/ECM) 2. Poor DPF Regeneration DOC failure = insufficient heat → DPF cannot regenerate properly. Signs: Frequent regens Incomplete regens DPF clogging DPF-related derate 3. Excessive Soot or Smoke If the DOC isn’t oxidizing hydrocarbons and soluble organics, you may notice: Visible black smoke Oily soot in exhaust stack 4. Low Exhaust Temperatures The DOC is responsible for increasing exhaust temp before the DPF. If it's damaged, temp sensors downstream will show consistently low temps, causing: Delayed or failed regen cycles Poor SCR performance 5. Engine Derate or Power Loss Emissions system faults can trigger automatic power reduction to protect the engine and maintain compliance. Some trucks go into derate mode if DOC efficiency drops too low. 6. Fuel Efficiency Drop Faulty DOC can disrupt aftertreatment cycles, causing: More frequent regens Higher fuel consumption About the Manufacturer – Paccar: PACCAR Inc is a global technology leader in the design, manufacture, and customer support of premium light-, medium-, and heavy-duty trucks. Founded in 1905 and headquartered in Bellevue, Washington, PACCAR is best known for its world-class truck brands: Kenworth, Peterbilt, and DAF. PACCAR’s trucks are recognized for their durability, fuel efficiency, advanced engineering, and driver-focused technology. In addition to truck manufacturing, PACCAR also designs and builds diesel engines, and provides financial services, information technology, and aftermarket support to its global customer base.