O2 Oxygen Sensor Downstream for Lincoln MKS MKT MKZ (2013-2015) 3.7L

Direct-Fit Downstream Oxygen Sensor Pair for 2013-2015 Lincoln MKS, MKT, MKZ (D3, D4, CD4)

What it Does: The Downstream Oxygen Sensor Set monitors catalytic converter efficiency on the 2013-2015 Lincoln MKS, MKT, and MKZ to eliminate check engine lights, verify emissions compliance, and preserve optimal air-fuel trimming.

The Stock Lincoln MKS,MKT,MKZ Sensor Degradation

Factory post-catalytic oxygen sensors on the 3.7L Duratec 37 (Cyclone) V6 undergo severe thermal cycling inside the tightly packed exhaust tunnel. Over time, soot contamination, unburnt hydrocarbons, and internal ceramic element aging slow down sensor response times. This degradation typically triggers persistent catalytic efficiency DTCs such as P0420 and P0430, forcing erratic long-term fuel trim modifications, elevated tailpipe emissions, and failed state inspection cycles.

The Engineering Solution

Engineered to resolve diagnostic DTCs, this direct-fit downstream pair features planar zirconia sensing elements with fast-acting integrated heaters that achieve operating temperature rapidly. Built with 304 stainless steel threaded shells, dual-layered external protective sleeves, and high-temp cross-linked harness wiring, these sensors resist thermal shock and road debris. Factory-matched pin terminals snap cleanly into OEM engine harnesses without requiring wire splicing, matching OEM standards including BE5Z-9G444-A, 234-4490, and BH6Z-9G444-A.

What's Included

• 2x Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2013-2015 Lincoln MKS 3.7L V6 (Downstream)
• 2013-2015 Lincoln MKT 3.7L V6 (Downstream)
• 2013-2015 Lincoln MKZ 3.7L V6 (Downstream)

Frequently Asked Questions & Fitment Warnings

Does this fit the D3, D4, and CD4 MKS, MKT, MKZ?

Yes, this is a direct fit for the 2013-2015 Lincoln MKS, MKT, and MKZ equipped with the 3.7L Duratec 37 engine; confirm your engine displacement prior to ordering as 2.0L EcoBoost and 3.5L EcoBoost variants require different harness configurations.

Are these sensors pre-threaded with anti-seize compound?

Yes, direct-fit replacement oxygen sensors include factory-applied high-temperature anti-seize on the stainless steel threads to prevent galling during installation.

The Lincoln Caliber

Restoring downstream sensor operation ensures accurate catalyst monitoring, clean diagnostics, and factory-level fuel control on Lincoln's modern luxury platforms.