O2 Oxygen Sensor Upstream Downstream for GMC Yukon XL (2015-2018) 5.3L, 6.2L

Direct-Fit Upstream and Downstream Oxygen Sensor Kit for 2015-2018 GMC Yukon (K2XX)

What it Does: The 4-piece oxygen sensor kit restores closed-loop AFR feedback and catalyst monitoring on the 2015-2018 GMC Yukon to resolve diagnostic trouble codes and restore stoichiometric fuel economy.

The Stock GMC Yukon Sensor Degradation

Factory zirconia O2 sensors on the K2XX platform suffer from gradual thermal fatigue and particulate fouling over extended mileage. In the direct-injected EcoTec3 V8 architectures (L83 and L86), carbon soot, unburned hydrocarbons, and continuous exhaust gas heat degrade the internal ceramic sensing element and heating circuits. This causes lazy voltage switching between lean and rich cycles, throwing fault codes such as P0131, P0137, P0151, P0420, or P0430, forcing the ECM into safe-mode rich fuel trims that ruin fuel mileage and foul spark plugs.

The Engineering Solution

This 4-piece replacement set refreshes both upstream wideband/air-fuel or heated sensors and downstream post-cat monitoring positions simultaneously. Built with fast-acting planar ceramic heating elements, double-laser-welded stainless steel protective shielding, and pre-applied anti-seize on the threads, these sensors deliver rapid light-off and steady mV response across extreme exhaust gas temperatures. Factory-terminated OEM-style pigtail harness connectors eliminate wire splicing, ensuring direct OE pin-to-pin communication with the vehicle ECU.

What's Included

• 2 x 234-4940 Oxygen Sensors
• 2 x 234-4974 Oxygen Sensors

Technical Specifications

Compatibility

• 2015-2018 GMC Yukon 5.3L V8
• 2015-2018 GMC Yukon 6.2L V8
• 2015-2018 GMC Yukon XL 5.3L V8
• 2015-2018 GMC Yukon XL 6.2L V8

Frequently Asked Questions & Fitment Warnings

Does this fit the K2XX Yukon?

Yes, this is a direct fit for the 2015-2018 GMC Yukon equipped with the 5.3L L83 and 6.2L L86 EcoTec3 engines.

Do I need special tools or PCM recalibration after installation?

No calibration tune is required, but an O2 sensor socket (7/8-inch / 22mm) is strongly recommended for removal and torquing to OE specs.

The GMC Heavy-Duty Reliability

Full-size GM SUV platforms demand accurate feedback to protect catalytic converters under heavy towing conditions, ensuring peak engine efficiency and consistent pulling torque mile after mile.