Denso 234-4156 Oxygen Sensor - Upstream
OE Quality 60-Day Returns
Denso
 OE Style

Denso 234-4156 Oxygen Sensor - Upstream

Brand Denso 234-4156
Position Upstream
Sensor Type Heated
Universal Or Specific Fit Specific
Wire Quantity 4
Wiring Harness Length 12.20
Product line OE Style
Fits Toyota · 9 vehicles

OE style replacement. Precision-built for an exact, first-time fit.

Heated sensor. Helps maintain accurate emissions control performance.

Exclusive trap layer. Protects the ceramic element for longer service life.

Cross-references ACDelco 213-1437, BorgWarner OS1981 and Bosch 13422 for the same application. See all 8.

$72.41Free shipping
In stock · usually ships same day before 1pm CST
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Denso OE Style Oxygen Sensor 234-4156

Denso 234-4156 is a heated, specific-fit oxygen sensor built to OE-style dimensions for direct replacement on select Toyota applications. It is engineered for accurate exhaust feedback, stable engine management, and consistent drivability on the vehicles listed below.

Key Features

  • Heated oxygen sensor for faster operating readiness
  • Specific fit for direct replacement on the listed Toyota models
  • 4-wire design for proper signal and heater circuit operation
  • 12.20 in. wiring harness length
  • OE Style construction for exact replacement fitment
  • Aluminum oxide trap layer helps protect the ceramic element from silicone and lead contamination

OE Style Construction

Denso’s OE Style line is built to match original equipment fit and function for the application. Part number 234-4156 is made for precise replacement on Toyota MR2 and Toyota Celica upstream locations, helping maintain accurate air-fuel feedback for the engine control system. This part cross-references Toyota 8946529365 for the same application.

Vehicle Fitment

  • Fits 1991-1995 Toyota MR2, upstream.
  • Fits 1990-1993 Toyota Celica, upstream.

Common Issues Addressed

  • Check engine light related to oxygen sensor performance
  • Incorrect air-fuel ratio readings from a worn upstream sensor
  • Reduced fuel economy caused by slow or inaccurate exhaust feedback
  • Rough idle or hesitation tied to sensor degradation
  • Emissions test failures caused by a faulty oxygen sensor

Installation Notes

Verify the connector style, wire count, and harness length before installation. This Denso oxygen sensor is a specific-fit replacement for the listed Toyota MR2 and Toyota Celica upstream applications, so confirm the vehicle year and position match the catalog listing before ordering. Follow factory service procedures for removal, thread preparation, and sensor routing to avoid damage to the harness or sensing element.

Quality Assurance

Denso manufactures and tests this oxygen sensor to OE standards for fit, function, and durability. The design includes contamination protection for the sensing element and is intended to deliver consistent performance in the specified Toyota applications.

Related reading

This part fits 9 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelPositionNotes
1995ToyotaMR2UpstreamOE Style
1994ToyotaMR2UpstreamOE Style
1993ToyotaCelicaUpstreamOE Style
1993ToyotaMR2UpstreamOE Style
1992ToyotaCelicaUpstreamOE Style
1992ToyotaMR2UpstreamOE Style
1991ToyotaCelicaUpstreamOE Style
1991ToyotaMR2UpstreamOE Style
1990ToyotaCelicaUpstreamOE Style
Directly replaces or cross-references 8 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
ACDelco — 213-1437BorgWarner — OS1981Bosch — 13422NTK — 24556Standard Ignition — SG359Toyota — 8946529365Walker Products — 250-24156Walker Products — 350-34252