Walker 350-34444 Oxygen Sensor - Downstream, Downstream Front or Downstream Rear
OE Quality 60-Day Returns
Walker
 Walker Products Aftermarket

Walker 350-34444 Oxygen Sensor - Downstream, Downstream Front or Downstream Rear

Brand Walker 350-34444
Position Downstream Rear
Connector Gender Male
Connector Shape Radiused Polygon
Mounting Type Threaded
Overall Length 21.77
Sensor Type Heated
Thread Diameter 18.0
Universal Or Specific Fit Specific
Wire Gauge Measurement 20
Wire Quantity 4
Wiring Harness Length 18.23
Product line Walker Products Aftermarket
Fits Toyota · 16 vehicles

OE replacement. Engineered to match original equipment sensor requirements.

Heated sensor. Provides the feedback needed for accurate engine management.

Threaded mount. Installs with a secure, threaded connection.

$72.15Free shipping
In stock · usually ships same day before 1pm CST
Step 1 — Confirm fitment
Free return shipping if it doesn't fit when you check fitment here first.

Select your vehicle to confirm fitment
Verify this part fits before purchasing — free returns if it doesn't
Step 2 — Quantity
Order total $72.15
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.
Not what you need? See all Oxygen Sensor options

Walker 350-34444 Oxygen Sensor for Toyota Sienna

Walker Products 350-34444 is a heated oxygen sensor built as a specific-fit OE-style replacement for select Toyota Sienna applications. It is engineered to provide the ECU with the feedback needed for downstream emissions monitoring, helping maintain proper engine management on the listed vehicles.

Key Features

  • Heated oxygen sensor for downstream emissions feedback
  • Specific fitment for select Toyota Sienna models
  • Threaded mounting type with 18.0 mm thread diameter
  • 4-wire design with 20-gauge wiring
  • Radiused polygon male connector for application-specific connection
  • Wiring harness length: 18.23 in.; overall length: 21.77 in.

Product Details

Walker Products Aftermarket focuses on engine management and oxygen/air-fuel sensors engineered for direct replacement use. Part number 350-34444 is built for the correct sensor location and fitment position on the vehicle, making it a practical choice for Toyota Sienna downstream oxygen sensor replacement service. This part cross-references no listed alternate part numbers in the provided data.

Fits 2011 Toyota Sienna, downstream front. Fits 2011-2012 Toyota Sienna, downstream. Fits 2012-2014 Toyota Sienna, downstream rear. Fits 2015 Toyota Sienna, downstream rear.

Common Issues This Sensor May Address

  • Check engine light related to oxygen sensor performance
  • Poor fuel economy caused by inaccurate exhaust feedback
  • Elevated exhaust emissions from a failing downstream sensor
  • Stored ECU fault codes tied to the affected sensor circuit
  • Rough engine operation when emissions feedback is compromised

Installation Notes

Verify the exact sensor position before installation, since Toyota Sienna applications in this range use different downstream locations. Inspect the sensor wiring harness and connector for damage before replacement, and confirm the threaded mounting point is clean and undamaged. Use the vehicle’s fault codes and service information to match the correct downstream bank and sensor position.

Quality Assurance

Walker Products manufactures engine management sensors as OE replacement components for global vehicle applications and operates as an ISO 9001/TS 16949 certified company. Since 1946, the brand has supplied oxygen and air-fuel sensor solutions for automotive service needs.

Related reading

This part fits 16 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelSubmodelLitersCylindersFuel TypePositionNotes
2015ToyotaSiennaXLE3.5LV6GASDownstream RearAl 09/2014; Downstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaSE3.5LV6GASDownstream RearAl 09/2014; Downstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaLimited3.5LV6GASDownstream RearAl 09/2014; Downstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaLE3.5LV6GASDownstream RearAl 09/2014; Downstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaL3.5LV6GASDownstream RearAl 09/2014; Downstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaXLE3.5LV6GASDownstream RearDownstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaSE3.5LV6GASDownstream RearDownstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaLimited3.5LV6GASDownstream RearDownstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaLE3.5LV6GASDownstream RearDownstream; Rear; To 09/2014; Walker Products Aftermarket
2015ToyotaSiennaL3.5LV6GASDownstream RearDownstream; Rear; To 09/2014; Walker Products Aftermarket
2014ToyotaSienna—3.5LV6GASDownstream RearRear downstream oxygen sensor must be installed in correct position.; Walker Products Aftermarket
2013ToyotaSienna—3.5LV6GASDownstream RearRear downstream oxygen sensor must be installed in correct position.; Walker Products Aftermarket
2012ToyotaSienna—3.5LV6GASDownstream RearRear downstream oxygen sensor must be installed in correct position.; Walker Products Aftermarket
2012ToyotaSienna—2.7LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket
2011ToyotaSienna—3.5LV6GASDownstream FrontDownstream front oxygen sensor required.; Walker Products Aftermarket
2011ToyotaSienna—2.7LL4GASDownstreamFits downstream bank 1 sensor 2 on specific vehicle models.; Walker Products Aftermarket