ACAUTO Oxygen Sensor 4-Pack for GM Trucks & SUVs (234-4012 & 234-4018) - Direct-Fit, Heated O2 Sensors

ACAUTO 4-pack oxygen sensors (234-4012 & 234-4018) are direct-fit upstream and downstream replacements engineered to restore accurate exhaust oxygen readings for GM trucks and SUVs.

If your Check Engine light flagged an O2 sensor, or you want to restore fuel efficiency and smooth running after age or contamination, this ACAUTO four-pack supplies the common upstream and downstream sensor positions used across many GM models. These sensors match OE fitment and wiring, use durable materials, and include pre-coated threads for straightforward install. The set covers Silverado, Tahoe, Suburban, Sierra, Yukon, Escalade, Express and related C/K variants—refer to vehicle fit notes and sensor position before installation.

Which vehicles and positions do these sensors fit?

This 4-pack includes both part numbers 234-4012 and 234-4018 designed to match the original upstream (pre-catalytic converter) and downstream (post-catalytic converter) locations on a range of GM V8 and V6 trucks and SUVs. It's intended for 1500/2500/3500 series Silverado, Sierra, Tahoe, Suburban, Yukon/Yukon XL, Escalade, Express and similar platforms from compatible model years.

• Direct replacements for 234-4012 and 234-4018 OE positions.
• Interchangeable with OE numbers 9617178, SG454, SG236, 13474.
• Fits Chevy, GMC, Cadillac, and GM-branded vans and trucks—verify sensor location.

How do these sensors ensure accurate readings and longevity?

ACAUTO sensors use a mix of robust materials and tested heater designs to reach operating temperature quickly and withstand exhaust conditions. The sensing elements and housings are built from platinum, ceramic and 310S stainless steel to resist corrosion and thermal cycling, helping preserve reliable oxygen measurement over time.

• Platinum and ceramic sensing element for stable signal output.
• 310S stainless steel body for corrosion resistance.
• Fast-acting heater shortens warm-up time to improve closed-loop performance.

What makes installation straightforward and trouble-free?

These are true direct-fit replacements with OE-style connectors and harnesses that match factory wiring, so you avoid splicing or adapters in most applications. Threads arrive pre-coated with anti-seize to prevent galling and simplify future removal, while the pack of four covers both upstream and downstream banks.

• OE-fit connectors and harness compatibility for plug-and-play installation.
• Pre-applied anti-seize on threads to protect during install and removal.
• Pack of four provides complete coverage for both banks on most dual-bank engines.

When should I replace these sensors and what symptoms suggest failure?

Consider replacement when the vehicle exhibits a persistent Check Engine light tied to oxygen sensor codes, rough idle, decreased fuel economy, or failed emissions testing. Age, contamination from oil or coolant, and physical damage can degrade sensor response—replacing with direct-fit sensors restores correct oxygen feedback for the engine control module.

• Common alerts: O2 sensor diagnostic codes or reduced fuel efficiency.
• Replace affected upstream/downstream sensors for accurate air-fuel control.
• Use this 4-pack when both banks require replacement or you want a ready spare set.

Who is this for? Technicians, DIY mechanics and fleet managers who need a dependable, OE-compatible replacement for GM trucks and SUVs will value this ACAUTO 4-pack. It suits owners of Silverado, Sierra, Tahoe, Suburban, Yukon, Escalade and related Express/Savana models who want an affordable, durable oxygen sensor solution that simplifies installation and helps restore proper engine management and emissions performance. Always check vehicle year, engine and sensor position to confirm exact fit before ordering.