YAOPEI O2 Oxygen Sensor 4-Pack for Chevrolet GMC V8 1996–2002 (2 upstream 234-4012 + 2 downstream 234-4018)

YAOPEI 4-pack O2 oxygen sensors (2x 234-4012 upstream + 2x 234-4018 downstream) restore accurate exhaust sensing for select Chevrolet, GMC and Cadillac V8 applications from 1996–2002.

These four replacement oxygen sensors are designed to match multiple factory part numbers and fit a range of full-size trucks, vans and SUVs from Chevrolet, GMC and certain Cadillac Escalade years. The set includes two upstream (pre-catalyst) and two downstream (post-catalyst) sensors so you can refresh the whole bank of sensors in one service. Each sensor uses a stainless housing with anti-oxidant treatment and laser-welded construction intended to resist heat and corrosion.

Will these sensors fit my 1999–2002 Silverado or Sierra?

If your vehicle is listed in the compatible years and models, the YAOPEI sensors are offered as direct replacements for the specified factory part numbers. Confirm year, make, model and engine before ordering, and compare the connector shape and pin layout to your existing sensor to avoid mismatch.

• Compatible with 1999–2002 Silverado 1500 and GMC Sierra 1500
• Also fits 1999–2000 Silverado/Sierra 2500 and many 1996–2002 full-size models
• Includes two upstream (234-4012 style) and two downstream (234-4018 style) sensors
• Check plug shape and interchange numbers (9617178, SG454, SG236, 13474) if unsure

How are these sensors built to withstand exhaust conditions?

The sensors feature stainless steel housings with a dual laser-welded seam for a tight seal that resists moisture intrusion. An anti-oxidant coating reduces oxidation at high temperatures, and the sensing element is pre-tested to help ensure reliable operation out of the box.

• Dual laser welded stainless housing for improved sealing
• Anti-oxidant coating for oxidation and heat resistance
• Factory-style wiring and plug to match original connectors
• Each sensor tested before packing to ensure function

What’s included and how easy is installation?

The package supplies four oxygen sensors: two front (upstream) and two rear (downstream). Installation is bolt-on with no modification required when the connector and thread type match your vehicle; basic hand tools and an oxygen sensor socket are typically all you need.

• 4 PCS total: 2 upstream (234-4012) + 2 downstream (234-4018)
• Straight bolt-on replacement—no cutting or splicing required
• Recommended tools: oxygen sensor socket, ratchet, anti-seize (if desired)
• Inspect and compare plug photos to confirm fit before installation

Which vehicles and part numbers do these replace?

This kit is built to interchange with several OE/aftermarket numbers and is intended for late-1990s through early-2000s Chevrolet, GMC and some Cadillac V8 models. Use the listed interchange numbers to cross-check compatibility with your vehicle’s original sensor.

• Interchange: 9617178, 234-4012, SG454 and SG236, 13474, 234-4018
• Fitment includes Avalanche, C/K series, Express/Savana vans, Tahoe, Suburban, Yukon and Escalade model years shown
• Position: 2 upstream (pre-cat) and 2 downstream (post-cat)
• Always verify by YEAR/MAKE/MODEL/POSITION and connector photos

Who is this for: The YAOPEI four-sensor kit is aimed at DIY mechanics and repair shops working on late-1990s to early-2000s GM full-size trucks, SUVs and vans that need a full-bank oxygen sensor refresh. It suits owners who want to replace all sensors at once for consistent sensing performance and who will verify connector type and part interchange before purchase. If you are unsure about fitment, compare the pictures and plug details or contact the seller for confirmation prior to installing.