HQPASFY O2 Sensor 234-4012/234-4018 for Chevy GMC Cadillac V6/V8 — stainless steel OE-fit

HQPASFY 234-4012 / 234-4018 O2 sensor is a direct-replacement oxygen sensor engineered to restore correct air-fuel monitoring on compatible Chevy, GMC and Cadillac V6/V8 models from the mid-1990s through early 2000s.

If your truck or SUV is showing a check engine light tied to an oxygen sensor, rough idle, or reduced fuel economy, this HQPASFY replacement restores proper exhaust monitoring and helps the engine control module get accurate readings. The sensor is built with a corrosion-resistant stainless steel housing and double laser-welded seams for long-term sealing in high-temperature exhaust environments. It replaces OE part numbers including 234-4012 and 234-4018 and fits a wide range of Chevy, GMC and Cadillac vehicles.

Which vehicles and engine sizes will this oxygen sensor fit?

This HQPASFY sensor covers many GM trucks and vans from approximately 1996–2002, including both 4.3L V6 and several 5.0L, 5.3L and 5.7L V8 applications. Check the specific model year and engine displacement to confirm compatibility before ordering.

• Chevy: Avalanche, Silverado, Suburban, Tahoe, Express vans across listed years and engines.
• GMC: Sierra, Yukon, C/K trucks, Safari and Savana vans with matching engine sizes.
• Cadillac: Escalade models listed for 1999–2002 with 5.3L and 5.7L options.
• Replaces OE numbers 234-4012, 234-4018 and common cross-reference codes.

How is the HQPASFY sensor constructed for durability?

The sensor uses high-temperature, corrosion-resistant materials and a stainless steel body to withstand harsh exhaust conditions. Double laser-welded seams and a fully submersible design improve sealing longevity, reducing the chance of exhaust leaks or early failure.

• Stainless steel housing resists rust and heat cycling.
• Double laser-welds provide a durable, leak-resistant joint.
• Submersible construction helps prevent moisture intrusion and contamination.
• Engineered to match OE form, fit and basic electrical requirements.

Will installing this sensor clear codes and improve fuel economy?

Replacing a faulty oxygen sensor can help the engine control system return to correct air-fuel management, which often clears related diagnostic trouble codes and can normalize fuel usage. However, results depend on overall engine condition and whether other sensors or systems are involved.

• Can resolve O2-related diagnostic trouble codes when the sensor was the root cause.
• Helps the ECM receive correct oxygen readings for better fuel trim control.
• May not fix issues caused by catalytic converters, wiring faults, or fuel-system problems.

Who is this for: This HQPASFY 234-4012 / 234-4018 replacement oxygen sensor is intended for owners, mechanics and fleet operators who need a direct-fit O2 sensor for mid‑1990s to early‑2000s GM trucks, SUVs and vans. It’s appropriate for DIY installers and professional shops wanting a durable, OE-style sensor to restore proper exhaust monitoring and support engine performance on compatible Chevy, GMC and Cadillac models.